Disc cartridge with grooves for a recording and reproducing apparatus

ABSTRACT

A disk cartridge is provided for storing a recording disk in a space formed by fastening an upper half and a lower half. At least either the upper half or the lower half has a pair of groove portions defined on its right and left side surfaces from the front end to the central portion direction so as to oppose a mis-insertion preventing protrusion portion formed on a disk drive. Engagement concave portions which are engaged and held by the holding member disposed within the disk drive when the disk cartridge is loaded into the disk drive are provided on the inner surfaces of the groove portions.

This is a divisional of pending application Ser. No. 08/718,361, filedJan. 6, 1997, pending.

TECHNICAL FIELD

The present invention relates to a recording and reproducing apparatusfor use in recording and/or reproducing and recording and reproducinginformation in and/or from and in and from a recording medium stored ina cartridge, in particular, a magneto-optical disk.

BACKGROUND ART

In general, a magneto-optical disk apparatus for recording andreproducing a magneto-optical disk is known as a disk apparatus capableof recording and reproducing or recording and/or reproducing aninformation signal in and from or in and/or from a magneto-optical diskrotatably stored within a cartridge of a disk cartridge.

The magneto-optical disk apparatus generally comprises a cartridgeloading mechanism having a cartridge holder for holding a diskcartridge, a spindle motor disposed under the cartridge loadingmechanism for rotating a magneto-optical disk, a rotation mechanismincluding a disk table for holding a magneto-optical disk, an opticalpickup device located behind the rotation mechanism and having anobjective lens, an external magnetic field generating apparatus disposedabove the optical pickup device and having a magnetic head applyinghead, an elevation mechanism disposed ahead of the external magneticfield generating apparatus and the optical pickup device for elevatingthe rotation mechanism, etc.

In the thus arranged magneto-optical disk apparatus, after the diskcartridge is conveyed to a predetermined cartridge loading position, themagneto-optical disk is rotated at this cartridge loading position andan information signal is written in and read out from themagneto-optical disk.

In such a conventional magneto-optical disk apparatus, a sliderapparatus for moving a cartridge holder with the disk cartridge heldthereon between a loading position and an unloading position has camportions formed on right and left portions thereof for supporting thecartridge holder. It is difficult to form the cam portions with a properpositioning relation therebetween. As a consequence, it is frequentlyobserved that the cartridge holder cannot be moved smoothly. Moreover,the cartridge holder is skewed so that the disk cartridge cannot beinserted into and ejected from the cartridge holder satisfactorily.

DISCLOSURE OF THE INVENTION

In view of the aforesaid aspect, it is an object of the presentinvention to provide a recording and reproducing apparatus in which acartridge holder can constantly be supported at a correct position andmoved smoothly, a disk cartridge can be inserted into and extracted fromthe cartridge holder smoothly and information can be reliably recordedon or reproduced from and recorded and reproduced from a magneto-opticaldisk.

As shown in FIGS. 1 through 4, a recording and reproducing apparatusaccording to the present invention includes a holder in which acartridge with a recording medium stored therein is inserted and heldand the recording medium is loaded on or unloaded from the recording andreproducing apparatus for recording and/or reproducing information asthe holder is elevated and lowered. The recording and reproducingapparatus includes drive means on which the recording medium rests anddriving the recording medium for recording and/or reproducing operationand elevating means having cams for elevating operation formed at itsside portions for elevating and lowering the holder relative to therecording and reproducing position when slid in parallel to theinsertion direction of the cartridge. The elevating means includes firstand second slide members each having cam grooves defined on it sidesurfaces, the first and second slide members being coupled with apredetermined clearance such that the first and second slide members canbe relatively finely moved.

Further, the first slide member has a through-hole and the second slidemember has a protrusion which is engaged with the through-hole with aclearance.

Further, the elevating means elevates and lowers the drive meansrelative to the recording medium, whereby the recording medium rests onthe driving means.

Furthermore, the elevating means further includes a first elevatingmember with the driving means attached thereto and a second elevatingmember for rotatably supporting the first elevating member, the secondmember being elevated and lowered together with the first elevatingmember as the elevating means is slid.

The recording and reproducing apparatus according to the presentinvention includes a disk drive comprising a holder in which a diskcartridge is inserted and held, a slider engaged with the holder andslid so as to load and unload the disk cartridge at recording and/orreproducing position, a chucking member on which the disk stored withinthe disk cartridge loaded at the recording and/or reproducing positionrests and a motor for rotating the disk resting on the chucking member,in which the slider includes first and second sliders each having camgrooves formed at its side surfaces and the first and second sliders arecoupled with a predetermined clearance so as to be finely moved.

The recording and reproducing apparatus further includes elevating meansfor elevating and lowering the chucking member. This elevating meansincludes a first elevating member with a motor being attached theretoand a second elevating member for rotatably supporting the firstelevating member and elevated and lowered together with the firstelevating member in accordance with the movement of the slider.

Further, the recording and reproducing apparatus includes a supportingshaft for rotatably supporting the first elevating member relative tothe second elevating member. This supporting shaft is engaged with aninclined portion provided on the slider.

Further, the recording and reproducing apparatus includes a positioningmember for the chucking member fixed to a chassis and having a guidemember for guiding movement of the first elevating member.

Further, the disk cartridge includes a circular hole into which thechucking member is inserted and a square hole into which a recordingand/reproducing head is inserted when the disk cartridge is loaded onthe recording and/or reproducing position, and a bridge portion providedbetween the circular hole and the square hole for partitioning bothholes formed on the lower surface side, the positioning member includinga first supporting protrusion member for supporting a surroundingportion of the circular hole and a second supporting protrusion memberfor supporting the bridge portion.

Further, the second supporting protrusion portion has a height largerthat of the first supporting protrusion portion.

Further, the recording and reproducing apparatus includes a diskcartridge lock means provided in the holder for locking the diskcartridge within the holder when the disk cartridge lock means isengaged with the side surface portion of the inserted disk cartridge,the disk cartridge lock means for locking the holder when it is engagedwith the slider at the unloading position of the holder.

The recording and reproducing apparatus according to the presentinvention includes a disk drive apparatus composing a chucking memberwith a flat surface on which a disk rests, a motor for rotating thischucking member and a holding member for holding the motor, an elevatingmeans with the, holding member attached thereto for elevating andlowering the motor and a motor positioning means having a guide memberfor guiding elevating and lowering of the motor, the elevating meansincluding a first elevating member with the holding member attachedthereto and a second elevating member for rotatably supporting the firstelevating member and being elevated and lowered together with the firstelevating member.

Further, the recording and reproducing apparatus includes an operationmeans engaged with the first and second elevating member and whichelevates and lowers the motor when it is slid.

Further, the recording and reproducing apparatus includes a supportshaft for rotatably supporting the first elevating member relative tothe second elevating member, the support shaft being engaged with theoperation means.

Further, the disk is stored in the cartridge. The cartridge has on itslower surface a circular hole into which the chucking member is insertedand a square hole into which a recording and/or reproducing head isinserted and a bridge portion provided between the circular hole and thesquare hole for dividing both holes. The positioning means comprises afirst supporting protrusion portion for supporting a surrounding portionof the circular hole and a second supporting protrusion portion forsupporting the bridge portion.

Further, the second supporting protrusion portion has a height largerthan that of the first supporting protrusion portion.

The present invention includes a head driving apparatus which comprisesa magnetic head movable in unison with a carriage in which an opticalpickup is attached to the radius direction of the disk loaded at therecording position and applying a magnetic field to the disk and alifter means for elevating and lowering the magnetic head. The presentinvention includes a means engaged with said lifter means for lockingthe magnetic head from moving in the radial direction of the disk andmeans for releasing the magnetic head locked by the lock means inaccordance with the loading operation for loading the disk in therecording position.

Further, the lifter means includes an arm member rotatably attached tothe carriage and a holding member engaged with the arm member forholding the arm member at the upper and lower positions.

Further, the holding member is pivotally supported to the carriage by acamshaft with an eccentric cam portion formed at one end side thereof.When the camshaft is rotated, a rotational angle of the arm member ischanged, whereby upper and lower positions of the magnetic head relativeto the magnetic head is adjusted.

Further, the arm member includes an operation portion for rotating thearm member to float the magnetic head from the disk. The lock meanslocks the magnetic head from moving when engaged with the operationportion.

Further, the recording and reproducing apparatus includes a holder forholding the disk and a slider for loading and unloading the disk byelevating and lowering the holder. The lock releasing means releases themagnetic head from being locked in accordance with movement of theslider when the holder is lowered.

Further, the recording and reproducing apparatus includes a motor forunloading the disk by moving the slider and an unloading operation meansoperated from the outside for elevating the magnetic head and energizingthe lock means for locking movement of the magnetic head when the motoris deenergized.

Furthermore, the unloading operation means is driven by moving theslider from the outside.

The present invention includes an optical pickup device comprising afixed optical unit composing a laser light source and a detector fordetecting laser beam reflected on a disk and a carriage having anobjective lens for converging the laser beam emitted from the fixedoptical unit on a signal recording surface of the disk, the carriagebeing moved in the radial direction of the disk. The optical pickupdevice further comprises a holder for holding the objective lens, theholder having a coil for driving the objective lens in the focusingdirection and a base for attaching the holder to the carriage through aresilient member in such a manner that the holder can be displaced inthe focusing direction. The base includes a fixed portion fixed to thefixed surface provided on the carriage. The fixed portion comprisesfirst and second fixed portions bonded to the respective fixed portionsby one of a plurality of kinds of adhesives each having a differentproperty.

A plurality of kinds of adhesives contain an instant adhesive and anultraviolet-curing adhesive.

Further, the first and second fixed portions are composed ofthrough-holes defined on the base and engaged with a plurality of pinsformed on the fixed surface of the carriage.

Further, the second fixed portion is provided on the surrounding portionof the first fixed portion. The base is temporarily fixed to thecarriage by the instant adhesive and the base is finally fixed to thecarriage by putting the ultraviolet-curing adhesive into the first fixedportion.

Further, a plurality of kinds of adhesives contain a first adhesivehaving adhesive force against force having durability and a secondadhesive having adhesive force against instant impulse.

Further, the resilient member includes a pair of parallel leaf springs,and a tape-like member for suppressing vibration of leaf spring isattached to one of the leaf springs at its end portions on the holderside and the base side.

Further, one of the pair of leaf springs includes a flexibleinterconnection film formed along the leaf spring for supplying a drivecurrent from the base side to the coil.

Further, the flexible interconnection film is attached to the leafspring by the above-mentioned tape-like member.

Further, a part of the flexible interconnection film is fixed to thebase and the flexible interconnection film on the base includes landportions for supplying a test focusing current to the coil.

The present invention relates to a disk cartridge for storing arecording disk in a space formed by fastening an upper half and a lowerhalf. The upper half has a groove portion formed from the front end tothe direction of the central portion so as to oppose a mis-insertionpreventing protrusion portion formed on a disk drive. An engagementconcave portion which is engaged and held by the holding member disposedwithin the disk drive when the disk cartridge is loaded onto the diskdrive is provided on the inner surface of the groove portion.

Further, opening portions from exposing a part of the signal recordingsurface of the accommodated recording disk to the outside are formed onthe front surface portions of the upper half and a lower half. A shuttermember is slidably provided on the front surface portions so as to openand close these opening portions.

Further, the above-mentioned groove portion is formed on the left andright side surfaces of the upper half.

Furthermore, the bottom surface of the above-mentioned groove portion isformed from the upper half to the lower half.

Furthermore, the above-mentioned groove portion is substantially L-shapein cross section.

The present invention relates to a disk cartridge in which a recordingdisk is accommodated in a space formed by fastening an upper half and alower half. At least either the upper half or the lower half includes apair of groove portions defined on its right and left side surfaces fromthe front end to the central portion direction which are opposed tomis-insertion preventing protruded portions formed on the disk drivewhen the disk cartridge is inserted into the disk drive. Engagementconcave portions which are engaged and held with the holding memberdisposed within the disk drive when the disk cartridge is loaded ontothe disk drive are formed on the inner surfaces of the above grooveportions. On the other hand, a width from the bottom surface of thegroove portion to the bottom surface of the other groove portion issmaller than that of the 3.5-inch size microfloppy disk shell.

Further, the disk cartridge is substantially equal to or slightly largerthan a width of a microfloppy disk shell of which the maximum width is3.5 inches.

Further, the disk cartridge has a rib-shaped portion continued to thegroove portion and a dimension from the top portion of one rib-shapedportion to the top of the other rib-shaped portion is substantiallyequal to a width of 3.5-inch size microfloppy disk shell.

Further, a thickness of rib-shaped portion is smaller than that of the3.5-inch size microfloppy disk shell.

Further, the rib-shaped portions are formed on left and right sidesurfaces of the upper half.

Further, the diameter of the recording disk is 88 mm, the maximum sizeof the disk cartridge is 92 mm, and the width between the two grooveportions is 87 mm.

Furthermore, the groove portion is formed adjacent to the storage spaceof the recording disk.

The present invention relates to a disk drive including a holder forholding a disk cartridge, a loading means for moving this holder fromthe insertion and eject position to the recording and reproducingposition for recording and/or reproducing information, and a recordinghead for recording information on the disk stored within the diskcartridge at the recording and reproducing position. The holder includesan insertion mouth defined at the front side to receive the diskcartridge, left and right side portions opposing the left and right sidesurfaces of the inserted disk cartridge, guide portions elongated fromthese side surfaces for guiding the insertion of the disk cartridge anda mis-insertion preventing protrusion protruded from the inside of atleast one side portion of the left and right side portions so as tooppose the groove portion defined on the side surface of the inserteddisk cartridge. The protrusion is formed on the side portion of theholder with a predetermined width relative to the thickness direction ofthe inserted disk cartridge to inhibit the insertion of the 3.5-inchsize microfloppy disk.

Further, the protrusion is formed in the side portion of the holder atthe position displaced in the lower direction from the center positionrelative to the thickness direction of the inserted disk cartridge, andhas a spacing portion smaller than the thickness of the shell of the3.5-inch size microfloppy disk on the upper side of the protrusion.

Further, the spacing formed between the top of the protrusion formed onany one of the left and right side portions and the other side portionis smaller than the width of the shell of the 3.5-inch size microfloppydisk.

Further, the protrusion is formed on the left and right side surfaceportions of the holder.

Further, a spacing between two protrusions formed on the left and rightside portions is made smaller than the width of the shell of the3.5-inch size microfloppy disk.

Furthermore, the holder has on its upper surface opposite to theinsertion mouth defined an opening portion into which the recording headis inserted at the recording and reproducing position, and theprotrusion is protruded from the opening portion of the side portion tothe inner surface of the insertion mouth side.

In the recording and reproducing apparatus according to the presentinvention, since the elevating means for elevating and lowering thecartridge holder comprises the first and second slide members which arecoupled with a clearance, the two slide members can be adjusted so as toaccurately oppose the cam members. Also, the loading and unloading ofthe disk cartridge can be carried out stably and smoothly and thechucking of the disk can be carried out accurately.

Moreover, the head means can be stably and reliably opposed to the diskchucked and rotated. Also, the head means can be satisfactorily heldwhen the disk cartridge is loaded and unloaded. Furthermore, theobjective lens of the head means can be reliably and stably held and thefocusing can be adjusted with ease.

Furthermore, the mis-insertion of the 3.5-inch size microfloppy disk canbe prevented and only a predetermined magneto-optical disk can bereliably recorded and reproduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a main portion of a recordingand reproducing apparatus according to an embodiment of the presentinvention in a partly-exploded fashion.

FIG. 2 is a perspective view illustrating an outer appearance of arecording and reproducing apparatus and a disk cartridge according tothe embodiment of the present invention.

FIG. 3 is a perspective view illustrating an inside structure of therecording and reproducing apparatus according to the embodiment of thepresent invention.

FIG. 4 is an exploded perspective view illustrating a part of therecording and reproducing apparatus according to the embodiment of thepresent invention.

FIG. 5 is a perspective view illustrating a chassis of the recording andreproducing apparatus according to the embodiment of the presentinvention.

FIG. 6 is a perspective view illustrating a cartridge lock apparatus.

FIG. 7 is an exploded perspective view of a disk cartridge lockapparatus.

FIG. 8 is a perspective view illustrating a slider apparatus accordingto the embodiment of the present invention.

FIG. 9 is a left-hand side elevational view of a loading mechanismaccording to the embodiment of the present invention.

FIG. 10 is an exploded perspective view illustrative of a manner inwhich a spindle motor is attached to an elevating mechanism according tothe embodiment of the present invention.

FIG. 11 is a perspective view illustrative of an optical pickup deviceaccording to the embodiment of the present invention in apartly-exploded fashion.

FIG. 12 is a cross-sectional view of the optical pickup device accordingto the embodiment of the present invention.

FIG. 13 is a perspective view of an objective lens supporting apparatusaccording to the embodiment of the present invention.

FIG. 14 is a fragmentary cross-sectional view illustrating the objectivelens supporting apparatus shown in FIG. 13 in an enlarged scale.

FIG. 15 is a side view illustrative of a transmission gear according tothe embodiment of the present invention.

FIG. 16 is an exploded perspective view illustrative of a transmissionmechanism according to the embodiment of the present invention.

FIG. 17 is a side view illustrative of the transmission mechanismaccording to the embodiment of the present invention.

FIG. 18 is a rear view illustrating the transmission mechanism accordingto the embodiment of the present invention.

FIG. 19 is a cross-sectional view illustrating the transmissionmechanism according to the embodiment of the present invention.

FIG. 20 is a perspective view illustrating the disk cartridge from theupper surface side.

FIG. 21 is a perspective view illustrating the disk cartridge from thelower surface side.

FIG. 22 is a plan view illustrating in a partly cross-sectional fashiona manner in which a shutter releasing pin is engaged with the diskcartridge during the disk cartridge is being loaded on the cartridgeholder.

FIG. 23 is a plan view illustrating the manner in which the shutterreleasing pin starts to release a shutter member during the diskcartridge loading onto the cartridge holder.

FIG. 24 is a plan view illustrating the intermediate state in which theshutter member is released by the shutter releasing pin during the diskcartridge loading onto the cartridge holder.

FIG. 25 is a plan view illustrating a partly cross-sectional fashion amanner in which the shutter member is fully released by the shutterreleasing pin during the disk cartridge loading onto the cartridgeholder.

FIG. 26 is a cross-sectional view illustrating a part of FIG. 25 in anenlarged scale.

FIG. 27 is a left-hand side elevational view illustrating a manner inwhich the elevating mechanism is operated in the loading state.

FIG. 28 is a right-hand side elevational view illustrating a manner inwhich the elevating mechanism is operated in the loading state.

FIG. 29 is a side view illustrating a manner in which a lifter mechanismis operated in the unloading state.

FIG. 30 is a side view illustrating a manner in which the liftermechanism is operated in the intermediate state between the loadingstate and the unloading state.

FIG. 31 is a side view illustrating a manner in which the liftermechanism is operated in the loading state.

FIG. 32 is a perspective view illustrating in a partly-exploded fashiona cartridge holder according to another embodiment of the presentinvention.

FIG. 33 is a plan view illustrating a main portion of FIG. 32.

FIG. 34 is a plan view illustrating a manner in which a disk cartridgeis rejected from the cartridge holder shown in FIG. 33.

BEST MODE FOR CARRYING OUT THE INVENTION

A recording and reproducing apparatus applied to a magneto-optical diskapparatus according to the present invention will be described belowwith reference to the drawings.

Initially, a disk cartridge in which a magneto-optical disk loaded ontothis magneto-optical disk apparatus is rotatably stored will bedescribed with reference to FIGS. 20 and 21.

As illustrated, a disk cartridge 201 comprises a disk-shapedmagneto-optical disk 202 and a cartridge 203 for rotatably storingtherein the magneto-optical disk 202.

The magneto-optical disk 202 has a data recording area on which amagnetic recording layer is formed. An information signal is written inand read out from or written in and/or read out from the magneticrecording layer by a magneto-optical means. The magneto-optical disk 202has a signal recording surface formed on one major surface portionthereof and a disk-like chucking hub 202a made of a metal materialformed on a disk central portion.

On the other hand, the cartridge 203 comprises a pair of upper half 204and a lower half 205 each of which is substantially box-shaped to have aspace large enough to store therein the magneto-optical disk 202. Thecartridge is formed by fastening the upper half 204 and the lower half205. The cartridge 203 has a front surface portion 209 with a shutterreleasing member fitting portion 224 formed therein. A shutter releasingpin (described later on) of a cartridge holder engages with the shutterreleasing member fitting portion to close a cartridge opening portion.Mis-insertion preventing grooves 207a, 208a are defined in substantiallyfirst half portions of both side surface portions 207, 208 so as not tobe located at a disk storage portion as shown in FIG. 20. Pin fittingholes 228, 229 are defined in the inner surfaces of the grooves 207a,208a, i.e., on the front portions of the side surfaces of the lower half205 in succession to the mis-insertion preventing grooves 207a, 208a.Cartridge hold pins (described later on) are fitted into the pin fittingholes 228, 229 when the cartridge is inserted into the cartridge holder.According to this embodiment, a spacing between the two mis-insertionpreventing grooves 207a and 208a of the cartridge 203 is smaller than aminimum value of a width of a shell which is the case of 3.5-inch sizemicrofloppy disk. Moreover, a thickness of rib-shaped portion, which areside surface portions of the upper half 204 corresponding to themis-insertion preventing grooves 207a, 208a, is smaller than thethickness of the shell of the floppy disk.

Specifically, in FIGS. 20 and 21 showing the disk cartridge 201, a fullwidth L₁ of the cartridge 203 is 92.0 mm (±0.2 mm), a full length L₂ is97.0 mm (±0.3 mm), and a thickness L₃ of both side portions is 5.0 mm(±0.2 mm), respectively. Widths L₄, L₅ of both the mis-insertionpreventing grooves 207a, 208a are 2.5 mm (+0.3 mm/-0.0 mm), lengths L₆,L₇ are 38.5 mm, and depths L₈, L₉ are 3.0 mm (±0.2 mm), respectively.

Therefore, in the cartridge 203 of the disk cartridge 201 according tothis embodiment, a spacing between the two mis-insertion preventinggrooves 207a and 208a becomes substantially 87.0 mm and thicknesses L₁₁,L₁₂ of the rib-shaped portions, which are both side surface portions ofthe upper half 204 corresponding to the mis-insertion preventing grooves207a, 208a, are L₃ -L₈ and L₃ -L₉ and become substantially 2.0 mm,respectively. For the cartridge 203 of the disk cartridge 201 accordingto this embodiment, a full width of the shell of the 3.5-inch sizemicrofloppy disk is 90.0 mm (+0.4 mm/-0.1 mm), a full length is 94.0 mm(±0.3 mm), and a thickness is 3.3 mm (±0.2 mm), respectively.Accordingly, a spacing L₁₀ between the two mis-insertion preventinggrooves 207a and 208a of the cartridge 203 is smaller than the minimumvalue of the width of the shell of the 3.5-inch size microfloppy disk.Thicknesses L₁₁, L₁₂ of the rib-shaped portions which are both sidesurface portions opposing the mis-insertion preventing grooves 207a,208a of the upper half 2 are smaller than the thickness of the shell ofthe floppy disk, respectively.

The cartridge 203 has on its rear surface of the lower half 205 definedcartridge positioning engagement holes 225, 226 with which there areengaged cartridge positioning pins (will be described later on) forpositioning the disk cartridge 201 within the magneto-optical diskapparatus body in the horizontal direction. A mis-erase preventionmember 227 for determining whether or not an information signal can bewritten in the magneto-optical disk 202 is formed near the cartridgepositioning pin engagement hole 225. Further, the lower half 205 has onits surface defined a first opening portion 206 for exposing a part ofthe signal recording surface of the magneto-optical disk 202 and achucking hub 202a to the outside of the cartridge 201.

The first opening portion 206 is divided by a narrow thin couplingsurface 205a to provide a rectangular opening portion 206a and acircular opening portion 206b. The rectangular opening portion isdefined at substantially the central portion in the left and rightdirection between one side surface 207 and the other side surface 208 ofthe cartridge 203, extending from the front surface portion 209 side ofthe cartridge 203 to substantially the central portion in the front andback direction of the cartridge so as to expose a part of the signalrecording surface of the magneto-optical disk 202. The circular openingportion 206b is defined so as to expose the chucking hub 202a. When thedisk cartridge 201 is loaded into the magneto-optical disk apparatusbody, the chucking hub 202a is opposed to a disk table of a diskrotation drive mechanism (will be described later on) from the circularopening portion 206b and the signal recording surface of themagneto-optical disk 202 is opposed to an objective lens of an opticalpickup device (will be described later on) from the rectangular openingportion 206a.

As shown in FIG. 20, the upper surface 204 has at its position near thefront surface portion 209 of the cartridge 203 defined a second openingportion 216 opposing the rectangular opening portion 206a of the firstopening portion 206.

The second opening portion 216 is formed as a rectangular openingportion equivalent to the rectangular opening portion 206a of the firstopening portion 206 and which is large enough to expose a part of themajor surface portion of the other side of the magneto-optical disk 202to the outside of the cartridge 203. When the disk cartridge 201 isloaded into the magneto-optical disk apparatus body, the major surfaceof the other side of the magneto-optical disk 202 is opposed to amagnetic field applying head (will be described later on) from thesecond opening portion 216. The front surface portion 209 of thecartridge 203 has at its positions corresponding to the opening portions206, 216 formed recess concave portions 206c, 216a in order for themagnetic field applying head and the optical pickup device to easilyenter in a closely opposing relation to the respective major surfaceportions of the magneto-optical disk 202. Specifically, a thickness of acentral portion near the front surface portion 209 of the cartridge 203is reduced at its portions corresponding to the first and second openingportions 206 and 216.

The cartridge 203 has a shutter member 211 slidably attached thereto foropening and closing the two opening portions 206, 216.

The shutter member 211 of a deformed U-shape comprises a first shutterplate portion 212 for closing the first opening portion 206 of the lowerhalf 205 over the two opening portions 206a, 206b and a second shutterplate portion 213 provided in parallel to the first shutter plateportion 212 for closing the second opening portion 216 of the upper half204. A slide guide member 214 is fixedly elongated from the base endcoupling portion of the first shutter plate portion 212 and the secondshutter plate portion 213 in the closing direction and slidably engagedto the front surface portion 209 of the cartridge 203.

The first shutter plate portion 212 is a rectangular member narrowenough to close the two opening portions 206a, 206b of the first openingportion 206. The first shutter plate portion 212 is pressed at its tipend portion by a shutter hold down plate 215 and thereby prevented frombeing floated from the cartridge 203.

On the other hand, the second shutter plate portion 213 is a rectangularmember wide enough to close at least the second opening portion 216.

A thickness of the slide guide member 214 is substantially equal to thethickness of the thin central portion of the cartridge 203, i.e., theaforementioned thicknesses of the recess concave portions 206c and 216a.A torsion coil spring (not shown) is interposed between the slide guidemember 214 and the cartridge 203 in order to constantly spring-bias theshutter member 21 in the direction in which the first opening portion206 and the second opening portion 216 are closed.

In FIG. 20, arrows X denote directions in which the shutter member 211is moved between the position at which the shutter member closes the twoopening portions 206, 216 and the position at which the shutter memberopens the two opening portions 206, 216.

A magneto-optical disk apparatus for recording and/or reproducing aninformation signal on and/or from the magneto-optical disk 202 stored inthe thus arranged disk cartridge 201 will be described with reference toFIGS. 1 through 19.

As shown in FIG. 2, a magneto-optical disk apparatus according to thisembodiment comprises a chassis 1 of substantially U-shape incross-section, a housing (disk apparatus body) 3 having incorporatedtherein a variety of mechanisms for recording and reproducing themagneto-optical disk 202 in the disk cartridge 201 and a front panel 4provided at the front surface portion of the housing 3. The front panelis exposed to the outside when the magneto-optical disk apparatus isassembled into a computer body or sub-system, etc., for example.

The front panel 4 has a cartridge insert and eject mouth 5 for insertingand ejecting the disk cartridge 201 into and from the housing 3. A lid 6is rotatably attached to the front surface portion of the housing 3 toopen and close the cartridge insert and eject mouth 5, whereby themagneto-optical disk stored in the disk cartridge can be prevented frombeing smudged by dusts or the like. Further, the front panel 4 includesa light-emitting element 7 for displaying the manner in which themagneto-optical disk 202 is recorded and reproduced and an eject button8 for ejecting the disk cartridge 201.

As shown in FIGS. 1, 3 and 4, the housing 3 houses a cartridgeloading/unloading mechanism (A) having a cartridge holder 9 for holdingthe disk cartridge 201 such that the disk cartridge can be freelyinserted and ejected from the cartridge holder, a disk rotationmechanism (B) disposed under the cartridge loading/unloading mechanism(A) and having a spindle motor 10 for rotating the magneto-optical disk202 and a disk table (spindle holding member which will be describedlater on) for holding the magneto-optical disk 202, an elevatingmechanism (C) for elevating and lowering the disk rotation mechanism (B)in unison with the cartridge loading/unloading mechanism (A), an opticalpickup device (D) provided behind the disk rotation mechanism and havingan objective lens 12, an external magnetic field generating apparatus(E) provided above the optical pickup device (D) and having a magneticfield applying head for the magneto-optical disk 202, a lifter mechanism(F) disposed near the external magnetic field generating apparatus (E)for holding the magnetic field applying head at the loading position andthe unloading position, a drive mechanism (G) disposed on one side ofthe lifter mechanism (F) for applying a loading drive force to themagnetic field applying head, and a transmission mechanism (H) disposedbehind the cartridge loading/unloading mechanism (A) for transmitting aloading/unloading drive force to the lifter mechanism (F).

A chassis, generally depicted at reference numeral 1 in FIG. 5, includesguide groove portions 11 formed on the inner surfaces of side wallportions 1b, 1c near the front side from the center in the verticaldirection of a chassis bottom surface 1a in order to position the frontand back direction of the cartridge holder 9 and to guide the elevatingand lowering of the cartridge holder. The chassis 1 has standardsupporting portions 12 of the disk cartridge 201 provided at the frontand back positions across the two guide groove portions 11. A pluralityof bosses 14 each being protruded with a predetermined spacing in thecircumferential direction are located at the central portion of thefirst half portion of the chassis bottom surface 1a. A spindle motorpositioning member 15 having an opening portion 15a into which thespindle motor 10 is inserted and a pair of spindle elevating andlowering guide pins 15b downwardly protruded in an opposing relation tothe diametrical direction of the opening portion 15a is attached tothese bosses 14. On the upper surface of the positioning member 15 areformed a plurality of support protruded surfaces 15c, 15d which supportthe circumferential surface of the center circular opening portion 206bof the disk cartridge 201. The support protruded surface 15ccorresponding to a coupling surface 205a between the circular openingportion 206b and the rectangular opening portion 206a is formed higherthan other support protruded surface 15d. The other support protrudedsurface 15d may be formed continuously.

Embodiments of various mechanisms (A) to (H) for recording andreproducing the magneto-optical disk 20 will be described with referenceto FIG. 1 and FIGS. 3 through 19.

(A) Cartridge loading/unloading Mechanism

The cartridge loading/unloading mechanism (A) includes the cartridgeholder 9 comprising a shutter opening apparatus (A-a) for automaticallyopening the shutter member 211 of the disk cartridge 201 and a diskcartridge lock mechanism (A-b) for holding the disk cartridge 201.

As shown in FIG. 6, the cartridge holder 9 is flat and comprises arectangular cartridge insertion and extraction mouth 18 opened in thefront and back direction, a top plate 9a and a concave opening portion19 defined in the central portion of the latter half portion of the topplate. An external magnetic field generating apparatus can be insertedinto and extracted from the concave opening portion 19. The cartridgeholder 9 has on its both sides guide supporting portions 20 extendedbackwardly from the cartridge insertion and extraction mouth 18 forguiding the disk cartridge 201 when the cartridge 201 is inserted intoand extracted from the cartridge holder 9. The guide supporting portions20 have a plurality of insertion guide tabs 21 formed on the front endsthereof. The shutter opening apparatus (A-a) is provided on the topplate 9a of the cartridge holder 9.

The shutter opening apparatus (A-a) comprises a cam groove 22 having atrajectory for opening the shutter member 211 in unison with theinsertion operation of the disk cartridge 201 and a shutter opening pinsupporting member 24 having a shutter opening pin 23 movable within thecam groove 22.

The cam groove 22 is a cam groove comprising an inclined portion 22ainclined with an inclination to the insertion direction of the diskcartridge 201, an arcuate portion 22b elongated to the inclined portion22a and a straight-line portion 22c substantially in parallel to theinsertion direction of the disk cartridge 201.

On the other hand, the shutter opening pin supporting member 24 isformed as substantially V-shape comprising a front end portion 24a and arear end portion 24b each of which is substantially semi-circular shapeas seen from the top. The shutter opening pin supporting member 24further includes a guide groove 24c of oblong opening extended from therear end portion 24b in the longitudinal direction and with which aguide pin 25 with a flange erected at the rear portion of the top plate9a of the cartridge holder 9 is engaged. The chassis opening pinsupporting member 24 is constantly spring-biased by a tension coilspring 26 in the direction in which the shutter opening pin 23 ispositioned at the starting end portion of the cam groove 22.

A cartridge insertion position restricting tab 27 for restricting theinsertion direction position of the disk cartridge 201 is downwardlybent on the rear end of the top plate 9a of the cartridge holder 9 so asto be protruded in the inside of the cartridge holder 9. A protrudededge portion 28 opposing the opening portion 216 of the upper half 204side of the cartridge 203 from the rear edge inner surface to both sideedge inner surface is inwardly protruded in the peripheral edge of theconcave opening portion 19. In this protruded edge portion 28, a frontedge portion 28a located at substantially the central portion of the topplate 9a is served as a mis-insertion preventing means for floppy diskor the like. Both side edge portions 28b, 28c are served as guides forguiding the disk cartridge 201 when the disk cartridge is inserted,i.e., both side edge portions of the second opening portion 216 in theopened state are slidably opposed to the respective side edge portions28b, 28c. Moreover, one side edge portion 28b is served as a preventingmeans for preventing the opened shutter member 211 from being closedunintentionally.

Further, engagement pawl members 29, 29 for preventing mis-insertion ofthe cartridge are inwardly bent at the lower half portion of thecartridge holder 9 at its rear central portions of both side surfaces. Aspacing between the upper end edge of the engagement pawl members 29, 29and the inner surface of the top plate 9a is equal to or slightly largerthan the thickness of the side surface portion of the upper half 204opposing the mis-insertion preventing grooves 207a, 208a of the diskcartridge 201. An apparent spacing between the upper end edge of theengagement pawl member 29 and the lower end edge of the protruded edgeportion 28 is smaller than the thickness of the shell of the floppy diskas seen from the front direction.

Recesses 30 opened in and out the holder are formed between the frontends and the engagement pawl members 29 in both side surfaces of thecartridge holder 9 thereby to escape the protruded portions of the innersurface sides of both side wall portions 1b, 1c of the chassis 1. Acartridge pressing spring member 31 for urging the disk cartridge 201against the guide supporting portion 20 from the cartridge heightdirection is attached to the top plate 9a of the cartridge holder 9 soas to oppose the inside of the holder.

The cartridge pressing spring member 31 comprises a supporting portion31a fixed to the top plate 9a of the cartridge holder 9 and a cartridgepressing portion 31b which opposes the inside of the holder to contactwith the upper surface of the disk cartridge 201.

The cartridge holder 9 has at its substantially centers of both sidesurfaces, more specifically, between the engagement pawl members 29 andthe recesses 30 placed guide pins 32 which are engaged with the guidegrooves 11 of the chassis 1. The two guide supporting portions 20 haveon its inner edge sides first and second leg members 33a, 33b downwardlybent in the front and rear direction. First and second pins 33a, 33bwhich are engaged with an elevation cam groove formed in the sliderapparatus, which will be described later on, are inwardly protruded tothe first and second leg members 33a, 33b.

The disk cartridge lock apparatus (A-b) of the cartridge holder 9 willbe described with reference to FIGS. 6 and 7.

The disk cartridge lock apparatus (A-b) comprises a slide base 35movable in the insert and eject direction of the disk cartridge 201, alock arm 36 pivotally supported to the slide base 35 and which isengaged with the disk cartridge 201 in accordance with the insertion ofthe disk cartridge and an interlocking arm 37 pivotally supported to thecartridge holder 9 and which is rotated in unison with the slidingoperation of the slide base 35.

As shown in FIG. 6, the slide base 35 is provided on the rear portion ofone side portion of the cartridge holder 9 so as to become slidable inthe front and back direction. As shown in FIG. 7, the slide base 35 isof substantially U-shape in cross-section. Two guide grooves 38 ofoblong holes in the front and back direction are formed on a sidesurface portion 35a and engaged with guide pins 39 protruded from theside surface of the cartridge holder 9. An upper surface portion 35b isin slidable contact with the top plate 9a of the cartridge holder 9 anda lower surface portion 35c can be moved in the directions shown byarrows a in FIG. 6 under the condition that it is opposed to the lowersurface side of the guide supporting portion 20 with a predeterminedspacing.

A recess-shaped engagement groove 40 with which a first engagement pin,which will be described later on, of the interlocking arm 37 is providedon the front side portion of the lower surface portion 35c of the slidebase 35. A lock arm 36 is pivotally supported by a shaft pin 41 to therear end portion of the lower surface portion 35c of the slide base 35.

As shown in FIG. 7, the lock arm 36 has at its position near the pivotportion erected a trigger pin 42 which comes in contact with the frontsurface side of the disk cartridge 201. The lock arm 36 has at its frontend portion erected a cartridge hold pin 43 which is fitted into a pinfitting hole 228 defined on one side portion of the disk cartridge 201.A cam groove 44 is formed on the surface between the two pins 42 and 43and engaged with an engagement pin 45 protruded on the lower surface ofthe rear end of the guide supporting portion 20 of the cartridge holder9. The lock arm 36 is rotated such that the cartridge hold pin 43 islocated in the outside under spring force of the torsion spring 46.

The interlocking arm 37 is formed as substantially V-shape as seen fromthe top, and pivotally supported at its central portion by a shaft pin47 between the rear lower surface of the guide supporting shaft portion20 of the cartridge holder 9 and the lower surface portion 35c of theslide base 35. A first engagement pin 48 which is engaged with theengagement groove 40 defined in the slide base 35 is downwardlyprotruded from the outer end side of the interlocking arm 37. A secondengagement pin 49 which is engaged with the slider apparatus, which willbe described later on, is downwardly protruded from the inner end sideof the interlocking arm.

The thus arranged cartridge holder 9 is lowered by the slider apparatus(A-c) when the cartridge is loaded and elevated when the cartridge isunloaded.

As shown in FIG. 8, the slider apparatus (A-c) is formed by coupling aleft slider 51L and a right slider 51R, each being formed assubstantially L-shaped in a plan view, substantially symmetrically witha small clearance at the horizontal sides. Then, as shown in FIGS. 1 and3, the slider apparatus is placed on the bottom surface 1a of thechassis 1 by the spindle motor positioning member 15 from the front sideto both sides such that the slider apparatus can be slid in the frontand back direction.

First and second cam members 53a and 53b are vertically erected on thefront and rear portions of the outer side edge of the longitudinal sideportions of the left and right sliders 51L and 51R in accordance withthe first and second pins 34a, 34b of the cartridge holder 9. First-halfparallel cam grooves 54a, 54b of high position whose front end sides areopened and second-half parallel cam grooves 55a, 55b of low positionwhose rear ends are closed are continuously formed on the cam members53a, 53b and slidably engaged with the first and second pins 34a, 34b ofthe cartridge holder 9. Third and fourth cam members 56a and 56b forelevating and lowering an elevating mechanism of the disk rotationmechanism, which will be described later on, are vertically erected onthe front and rear portions on the inner side edge. The cam members 56a,56b have formed inclined cam grooves 57a, 57b each having a descendingslope.

On the rear portion of the inner side edge of the left slider 51L isformed an engagement member 59 in which an engagement groove 58 engagedwith the second engagement pin 49 of the interlocking arm 37 of theaforesaid disk cartridge lock apparatus (A-b) is formed in the directionperpendicular to the sliding direction (front and back direction) of theslider in parallel to the surface of the slider. On the other hand, aslide operation portion 60 is elongated backwards from the inner sideedge of the right slider 51R and a toothed portion 61 which is meshedwith a rotary damper member is provided at substantially the center ofthe outer edge. On the rear end portion of the slide operation portion60 of the right slider 51R are formed an engagement portion 60a which isengaged with the drive mechanism (G) and an operation pin 60b and anoperation member 60c for operating the transmission mechanism (H) side.

The left slider 51L and the right slider 51R are coupled together with asmall clearance in the inner end surface of the horizontal side portion.Specifically, an engagement hole 62 is defined on the inner end surfaceof the left slider 51L and an engagement protrusion 63 which is smallerin diameter than the engagement hole 62 is formed on the inner end ofthe left slider 51R, whereby the engagement hole 62 and the engagementprotrusion 63 are engaged with each other with a predeterminedclearance. Front and back oblong apertures 64a, 64b, 64c are defined onthe horizontal and vertical side portions of the two sliders 51L, 51Rand slidably engaged with guide shafts 65a, 65b, 65c erected on thebottom surface 1a of the chassis 1 in the front and back direction underthe condition that they can be prevented from being floated. A tensioncoil spring 67 is extended between the intermediate portions, i.e., theguide shaft 65b engaged with the front oblong aperture 64b on thelongitudinal side portion and a spring engagement member 66 at the rearend portion, whereby the two sliders 51L, 51R are constantlyspring-biased in the forward direction under spring force of the tensioncoil spring. FIG. 8 shows the manner in which the two sliders 51L, 51Rare slid in the rearward.

The cartridge loading/unloading mechanism A is constructed by assemblingthe cartridge holder 9 with the thus arranged slider apparatus (A-c).

Specifically, the cartridge holder 9 is fitted into the chassis 1 byengaging the guide pins 32 of the respective sides into the guidegrooves 1 of both sides from the upper surface side. The front and backfirst pin 34a and the second pin 34b of both sides are engaged with thefirst-half parallel cam grooves 54a, 54b of the first cam member 53a andthe second cam member 53b of the left and right sliders 51L, 51R.Furthermore, the second engagement pin 49 of the interlocking arm 37 ofthe disk cartridge apparatus (A-b) is opposed so as to be engaged withthe engagement groove 58 defined in the engagement member 59 of the leftslider 51L, thereby the cartridge loading/unloading mechanism A beingconstructed (see FIG. 9).

In the assembly of the cartridge holder 9 and the slider apparatus(A-c), the left slider 51L and the right slider 51R are separated andcoupled with a small clearance so that they become movable individuallyby a small amount. Therefore, even when a positional relationshipbetween the first and second pins of the cartridge holder 9 is slightlydisplaced, they can be engaged with the cam grooves of the left andright sliders 51L, 51R, respectively.

(B) Disk Rotation Mechanism

The disk rotation mechanism (B) includes a spindle motor 10 which can bemoved by an elevating mechanism (C) in the direction in which it comesclose to or away from the disk cartridge 201.

The spindle motor 10 is disposed within a spindle holding body 68comprising a rotary portion 68a having a concave portion which is openedin the upper direction (disk loading side) and a motor attachmentportion 68b opposing the lower peripheral edge of the opening portion15a of the spindle motor positioning member 15.

Within the concave portion of the rotary portion 68a of the holding body68 is housed a magnet 69 which attracts the chucking hub 202a of themagneto-optical disk 202. The magnet 69 has at its central portiondefined an insertion aperture 69a into which is provided the spindleshaft 10a of the spindle motor 10. A flat disk resting surface (disktable surface) 68a₁ on which the magneto-optical disk 202 rests isformed on the opening peripheral edge of the concave portion of therotary portion 68a. The height direction position of the disk restingsurface 68a₁ is set to be a little lower than the tip end of the spindleshaft 10a.

A pair of spindle elevating guide apertures 68b₁ into which a pair ofspindle elevating guide pins 15b are provided on the motor attachmentportion 68b of the spindle holding body 60 in an opposing relation withrespect to the diametrical direction.

(C) Elevating Mechanism

The elevating mechanism (C) comprises, as shown in FIG. 10, a firstelevating plate 70 of substantially rectangular shape in a plan viewdisposed between the bottom surface 1a of the chassis 1 and the spindlemotor positioning member 15 for holding the disk rotating mechanism (B)and a second elevating plate 71 of substantially U-shape in a plan viewfor rotatably supporting the first elevating plate 70 in the front andback direction and elevated and lowered in accordance with theloading/unloading operation of the disk cartridge 201, i.e., the frontand back direction sliding of the aforementioned slider mechanism (A-c).

The rotary portion 68a of the spindle holding body 68 is fitted into thefirst elevating plate 70 of the elevating mechanism (C). The firstelevating plate has defined an opening portion 72 to which the portionwith the two spindle elevating guide apertures 68b₁ of the motorattachment portion 68 formed therein is opposed, and has at its centerof both side surfaces protruded shaft pins 73 in the lateral direction.

The spindle holding body 68 of the spindle motor 10 is opposed to thefirst elevating plate 70 from the lower surface and the rotary portion68a is fitted into the opening 72. Also, under the condition that thecircumferential surface portion of the two spindle elevating guideapertures 68b, of the motor attachment portion 68b are opposed to thefirst elevating plate, the spindle holding body is fixed at its otherportion surface in which the motor attachment portion 68b is not exposedto the first elevating plate by setscrews.

On the other hand, cartridge positioning pins 74 for positioning thedisk cartridge 201 are implanted on the upper surfaces of the respectivesides near the front edge of the second elevating plate 71. Cam pins 75are laterally protruded on the inside of both side portions 71L, 71R insubstantially opposing to the positioning pins 74, and shaft pins 73 ofthe first elevating plate 70 are pivotally supported to the rear endportion of the two side portions 71L, 71R in parallel to the cam pin 75,whereby the first and second elevating plates 70 and 71 are coupled soas to become rotatable with each other.

The cam pins 75 of the second elevating plate 71 and the shaft pins 73of the first elevating plate 70 are respectively engaged with theinclined cam grooves 57a and 57b of the third cam member 56a and thefourth cam member 56b of the sliders 51L, 51R of the slider apparatus(A-c). This engagement is made with a small clearance. With thisengagement, the first and second elevating plates 70, 71 are disposed onthe bottom surface 1a of the chassis 1 so as to be coupled to thesliders 51L, 51R. When the sliders 51L, 51R are slid in the front andrear direction, the first and second elevating plates are elevated andlowered along the inclined cam grooves 57a of the third and fourth cammembers 56a, 56b. As a result, in the spindle motor 10 fixed to thefirst elevating plate 70, the rotary portion 68a of the spindle holdingbody 68 can be inserted into and extracted from the opening portion 15aof the spindle motor positioning member 15.

Detection switches 76A, 76B such as write-protect switch or disk typedetection switch are mounted on one side portion (left side portion) ofthe front end surface of the second elevating plate 71.

(D) Optical Pickup Device

The optical pickup device (D) is able to irradiate laser beams on thesignal recording surface of the magneto-optical disk 202 in the diskloading portion provided within the housing 3. As shown in FIG. 11, thisoptical pickup device (D) has a separate optical system whose movableportion is reduced in weight in order to cope with high-speed accessunlike a conventional unitary type optical system. Specifically, thisoptical pickup device comprises a fixed optical system 80 having a laserdiode serving as a light source for recording and reproducing, a signaldetector for focusing and tracking control and a signal detector fordetecting a recording signal, a carriage 82 having an objective lens 81for converging light beam from the fixed optical system 80 on the signalrecording surface of the optical magnetic disk 202 and a galvano mirror83 located behind the carriage 82 for carrying out the tracking control.The above-mentioned elements and parts are respectively provided on thechassis 1.

The separate optical system is disposed in substantially L-shape in aplan view such that the galvano mirror 83 becomes a corner portion andthe carriage 82 and the fixed optical system 80 become respective endportions.

The galvano mirror 83 reflects light beam emitted from the fixed opticalsystem 80, introduces reflected light beam into the optical system ofthe carriage 82 and executes a tracking control based on the change ofangle of the mirror reflection surface.

The carriage 82 is held by a pair of guide shafts 84 positioned over thechassis 1 and which are parallel to each other with a predeterminedspacing in the left and right direction so that it becomes freelyslidable. Two pairs of bearings 85 are provided on one side surfaceportion of the carriage 82 such that rotation shafts of bearings of eachpair are set at an angle of 90°. A pair of bearings 85 are provided onthe other side surface portion such that rotation shafts of bearings ofeach pair are set at an angle of 90° (see FIG. 12). The carriage 82 hasfixed thereto a resilient member for applying a spring force to one ofthe pairs of bearings 85 in the direction in which an angle between thepairs of bearing rotary shafts becomes smaller than 90°.

Carriage drive linear motors 86 are attached to the respective sides ofthe carriage 82. The linear motor 86 comprises a frame-shaped coil 87projected to both sides of the carriage 82, center yokes 88a, magnets 89and side yokes 88b each of which is opposed through a part of the coil87.

A lens holder 90 for holding an objective lens 81 is disposed on thecarriage 82 through two resilient members 91 provided in parallell inthe upper and lower direction. This lens holder 90 can be displaced by amagnetic circuit 92 in the focusing direction. The magnetic circuit 92comprises a frame-shaped coil 93 projected toward both sides of theobjective lens 81, a center yoke, a magnet and side yokes which areopposed to each other through a part of the coil 93.

Further, the carriage 82 has defined therein a beam passing aperture 82bfor introducing light beam from the fixed optical system 80 into theobjective lens 81 (see FIG. 12). A rising mirror 94 which is locatedjust under the objective lens 81 is fixed to the carriage 82.

In the thus arranged optical pickup device (D), when the objective lens81 is attached to the carriage 82, base ends of the two resilientmembers 91 such as phosphor bronze provided in the upper and lowerdirection for supporting the lens holder 90 are fixed to a base plate 95and this base plate 95 is fixed to the carriage 82.

As shown in FIGS. 11, 13, the base plate 95 has a plurality ofthrough-holes 96 (96a, 96b, 96c, 96d), i.e., three through-holes in theback and one through-hole in the front defined. On the base plate fixedsurface side of the carriage 82 are implanted three pins 97 (97a, 97b,97c) each of which has a diameter smaller than that of the through-hole96 in response to the three through-holes 96 defined at the back of thebase plate 95. Of the three pins 97, the center pin 97a is larger indiameter and shorter in length compared with the pins 97b, 97c on therespective sides.

When this base plate 95 is fixed to the carriage 82, as shown in FIG.11, the base plate 95 is brought in contact with the base plate fixingsurface by inserting the pins 97 into the through-holes 96. In thisstate, the base plate 95 can be moved relative to the carriage 82 in arange of a spacing between the through-holes 96 and the pins 97. Underthe condition that the optical axis of the objective lens 81 is properlyadjusted while moving the base plate 95, an instant adhesive is pouredinto the two through-holes 96b, 96c defined at the back and the centralthrough-hole 96a defined at the front to thereby temporarily fix thebase plate to the carriage. Then, an ultraviolet curing adhesive ispoured into the central through-hole 96a defined at the back and curedwith the irradiation of ultraviolet rays, whereby the base plate 95 isbonded to and fixed to the carriage 82. During the base plate 95 beingbonded to and fixed to the carriage 92, the instant adhesive is pouredinto the through-holes 96b, 96c, 96d and an accelerator is furtherpoured into the above through-holes, thereby quickening the curing ofthe instant adhesive.

As described above, when the base plate 95 for holding the objectivelens 81 is bonded to and fixed to the carriage 82, there are used twokinds of adhesives, i.e., the instant adhesive and theultraviolet-curing adhesive. Inasmuch as the instant adhesive is high intensile strength and the ultraviolet curing adhesive is strong against ashock, a bonding strength is increased and the base plate 95 is stronglyfixed to the carriage. Therefore, the base plate 95 is integrally formedwith the carriage 82.

As shown in FIGS. 13 and 14, of the two upper and lower resilientmembers 91 provided between the lens holder 90 for holding the objectivelens 81 and the base plate 95, a flexible interconnection film 98 whichis connected to the coil 93 is bonded to one resilient member 91 (upperresilient member in the illustrated example) through an adhesive layer99. This adhesive layer 99 is formed on the resilient member 91 throughan adhesive having a viscosity, e.g., acrylic adhesive. In thisembodiment, the tip end of the resilient member 91, i.e., the end of thelens holder 90 and the base end has a length, i.e., length of 1/3 of thefull length from the base plate 95 side end or a length shorter than 1/3to which the flexible interconnection film 98 is bonded. The flexibleinterconnection film is formed of a polyimide film and polyethyleneterephthlate (PET). When the flexible interconnection film 98 is bondedto the resilient member 91 through the adhesive layer 99, the adhesivelayer 99 becomes a damping agent and the flexible interconnection film98 becomes a constraint plate, thereby forming a damping material layeron the resilient member 98. A primary resonance frequency of theresilient member 91 is high and a resonance level is suppressed to below.

Therefore, a damping effect for the objective lens 81 can be maderemarkable with the result that light can be reliably converged on thesignal recording surface of the magneto-optical disk 202.

A land portion 98b is formed on a conductive pattern 98a at its positionof the upper surface of the base plate 95. When the focusing directionof the objective lens 81 is corrected, a test focusing current issupplied to the conductive pattern 98a by contacting a power-supplyterminal to the land portion 98b.

(E) External Magnetic Field Generating Apparatus

As shown in FIG. 4, the external magnetic field generating apparatus (E)includes a slider (hereinafter referred to as "magnetic field applyinghead") 100 incorporating therein a magnetic field applying head forapplying a predetermined external magnetic field to the signal recordingsurface of the magneto-optical disk 202. This magnetic field applyinghead 100 is held at the tip end of a head arm, which is resiliently heldon the upper surface of the rear end portion 82a of the carriage 82 soas to become swingable in the upper and lower direction, in an upwardlyopposing relation to the objective lens 81 of the optical pickup device(D). The magnetic field applying head 100 of the external magnetic fieldgenerating apparatus (D) is composed of a floating-type magnetic head soas to cope with a magnetic field modulation over-write. On the otherhand, in order to maintain a safety level with which the head isfloated, the head arm 100 is placed at the position in which themagnetic field applying head 100 is spaced apart from the signalrecording surface of the magneto-optical disk 202 in the disk unloadingstate and at the position in which the magnetic field applying head 100is brought in contact with the signal recording surface of themagneto-optical disk 202 by a pressing force of about several gram to 10gram in the disk loading state.

The head arm 100 can hold the magnetic field applying head by a liftermechanism (F) at the loading position in which the magnetic fieldapplying head 100 can apply a magnetic field to the magneto-optical disk202 and at the unloading position in which the magnetic field applyinghead 100 is spaced apart from this loading apparatus in the sideopposite to the disk resting surface 60c of the disk rotating mechanism(B).

(F) Lifter Mechanism

As shown in FIGS. 4 and 11, the lifter mechanism (F) comprises a lifterarm 111 attached to the rear end portion of the carriage 82 so as tobecome rotatable in the upper and lower direction and a lifter plate 112for holding the lifter arm 111 at the upper and lower positions. Thelifter arm 111 is of substantially L-shape, in a plan view, comprising ahorizontal side portion 111a on which the head arm 101 rests and avertical side portion 111b pivotally supported to the carriage 82. Anengagement plate 113 is integrally pivoted to the rear end portion ofthe vertical side portion 111b in response to the side surface of therear end portion of the carriage 82. A shaft pin 114 which is pivotallysupported to the carriage 82 is inwardly and horizontally implanted onthe front lower portion of the engagement plate 113. An operation pin115 is outwardly and horizontally implanted on the rear upper portion ofthe engagement plate. An upper-stage concave portion 116a of largediameter and a lower-stage concave portion 116b are formed on the frontedge portion and a concave portion 116c which is opened in the lowerdirection is formed on the lower portion.

The lifter plate 112 is interposed between the engagement plate 113 ofthe lifter arm 111 and the side surface of the rear end portion of thecarriage 82. A shaft aperture 117 of large diameter in which a protrudededge 117a is formed on the circumferential edge by burring (drawing) isprovided on the lifter plate 112. A short engagement pin 118 which isengaged with the concave portions 116a, 116b of the front edge portionof the engagement plate 113 is protruded on the outer surface side and along operation pin 119 is protruded on the outer surface side with adistance from the engagement pin 118. The short engagement pin 118 issubstantially the same in diameter as that of the lower-stage concaveportion 116b.

This lifter plate 112 is pivotally supported to the rear end sidesurface of the carriage 82 by a camshaft 120. The camshaft 120 is formedsuch that an eccentric cam portion 120b of substantially the samediameter as that of the shaft aperture 117 of the lifter plate 112 andwhich is inserted into the above shaft aperture is formed on one endportion side of the shaft portion 120a. A coarse surface portion 120c isformed on the circumferential surface of substantially the centralportion of the shaft portion 120a by narrow shaft direction grooves witha predetermined width (spline grooves), knurling or the like.

The camshaft 120 is inserted into and pivotally supported into a shaftaperture 121 defined on the rear end side surface of the carriage 82 inthe direction perpendicular to the moving direction such that theeccentric cam portion 120b is protruded on the side surface. In thisstate, the lifter plate 112 is rotatably disposed on the rear end sidesurface by fitting the shaft aperture 117 into the eccentric cam portion120b. A coil portion of the torsion coil spring 122 is inserted into anouter peripheral protruded edge 117a of the shaft aperture 117 of thelifter plate 112.

Then, the engagement plate 113 of the lifter arm 111 is pivotallysupported to the rear end side surface of the carriage 82 from the outersurface side of the lifter plate 112 by inserting the shaft pin 114 intoa shaft aperture 123 defined with a distance from the shaft aperture121. The concave portion 116a or 116b of the front edge portion isengaged with the engagement pin 118 of the lifter plate 112 and theconcave portion 116c of the lower portion is opposed across the outerend portion of the camshaft 120, thereby being retained and held by aretaining ring 124 fitted into the outer end of the camshaft 120. Inthis state, the operation pin 115 on the engagement plate 113 side andthe operation pin 119 on the lifter plate 112 side are opposed inparallel with a clearance. The engagement plate 113 and the lifter plate112 are engaged with both end portions of a torsion coil spring 122 andboth plates 113 and 112 are spring-biased in the opposite directions,whereby the two operation pins 115 and 119 are constantly biased so asto become distant from each other.

When the camshaft 120 is rotated, the position of the lifter plate 112is changed, whereby the state in which the engagement plate 113 of thelifter arm 111 is pressed by the engagement pin 118 is changed. As aresult, the angle of the lifter arm 111 is changed with the result thata swing angle of the head arm 101 is adjusted, thereby adjusting theupper and lower positions of the magnetic field applying head 100relative to the magneto-optical disk 202. In this state, an engagementmember 125 is attached to the carriage 82 in response to the insertedportion of the camshaft 120 and engaged with the coarse surface portion120c of the camshaft 120, resulting in the camshaft 120 being fixed tothe carriage 82.

(G) Drive Mechanism

As shown in FIG. 4, the drive mechanism (G) comprises a drive motor 130serving as a drive source for releasing the locked state of the liftermechanism (F) by a transmission mechanism (H), which will be describedlater on, a drive source for ejecting the disk cartridge 201 to theoutside of the housing 3 and a transmission gear 132 coupled to thedrive motor 130 and which has on its peripheral edge of an outer sidesurface a columnar pin 131 protruded in the direction perpendicular tothe direction in which the carriage 82 is moved. When the transmissiongear 132 is rotated in the direction shown by an arrow R₁ in FIG. 15,the pin 131 is moved from a fixed position (reference position) a to afixed position b, whereby the aforementioned slider apparatus (A-c) isreturned from the loading position to the unloading position. When thetransmission gear 132 is rotated in the direction shown by an arrow R₂in the same figure, the pin 131 is moved from the fixed position a tothe fixed position b so that an operation power is given to the liftermechanism (F) through a transmission mechanism (H) which will bedescribed later on.

Thus, when the transmission gear 132 is rotated in the direction shownby the arrow R₁ in FIG. 15 so that the pin 131 is displaced from thefixed position a to the fixed position b, the pin 131 is engaged withthe engagement portion 60a of the slide operation portion 60 of theright slider 51R of the slider apparatus (A-c) and presses the same inthe backward direction, whereby the slider apparatus (A-c) is slidbackwardly against the forward spring-biasing force to eject the diskcartridge 201. When the transmission gear 132 is rotated in thedirection shown by the arrow R₂ in FIG. 15 so that the pin 131 isdisplaced from the fixed position a to the fixed position b, the liftermechanism (F) is operated by driving the transmission mechanism (H). Ifthe carriage 37 is located at the outermost peripheral position, thenthe magnetic field applying head 100 is loaded onto the magneto-opticaldisk 202.

(H) Transmission Mechanism

As shown in FIGS. 16 through 19, the transmission mechanism (H)comprises a base 144 including a top plate portion 141 with bearingmembers 140 opposite to each other in the front and back direction, aside wall plate portion 142 elongated from the top plate portion 141 anda bottom surface plate portion 143 elongated from the side wall plateportion 142 and which is opposed to the top plate portion 141 in theupper and lower direction, a lock plate 145 pivotally supported to thetop plate portion 141 in the lateral direction, i.e., pivotallysupported to the top plate portion in the upper and lower direction inan opposing relation to the side surface side of the carriage 38 forengaging the carriage 38, an operation plate 146 coaxially pivoted tothe lower surface side of the lock plate 145, an operation lever 147pivotally supported to the side wall plate portion 142 and which isbackwardly rotated relative to the bottom surface plate portion 143 inthe upper and lower direction for operating the lifter mechanism (F), aslide plate 148 slidably attached to the outer surface side of the sidewall plate portion 142 in the front and back direction and which isslidably operated by the drive mechanism (G) to operate the operationplate 146 and the lift lever 147, a self-maintaining typeelectromagnetic clutch 149 disposed at the rear portion of the bottomsurface plate portion 143 for locking and holding the lift lever 147 inthe operated state, a lock arm 150 operated in a self-maintainingfashion by the electromagnetic clutch 149, a lock releasing plate 151for releasing the self-maintaining of the lock arm 150 in a manualfashion, etc.

Shaft apertures 140a are defined in both the bearing members 140 of thetop plate portion 141 of the base 144 of the transmission mechanism (H)in an opposing relation to each other in the front and rear directionand a horizontal oblong aperture 152 is defined in the side wall plateportion 142.

On the lock plate 145 pivotally supported to the top plate portion 141side of the base 144 are downwardly bent supporting surface portions 153which are inwardly opposed to the two bearing members 140 of the topplate portion 141. On the side opposing the carriage 82 is downwardlybent an engagement surface portion 155 having at its tip end acomb-shaped tooth portion 155a which are engaged with the operation pin115 of the lifter arm 111 of the lifter mechanism (F). A cam surfaceportion 156 which is downwardly protruded is provided on the sideopposite to the engagement surface portion 155. A return leaf spring 157is attached to the upper surface of the lock plate 145, and a free end157a thereof is spring-biased in the upper direction.

On the other hand, on the operation plate 146 is downwardly formed acontact surface portion 158 which is inwardly opposed to the twosupporting surface portions 153 of the lock plate 145, and a bearingportion surface 158b having a shaft aperture 158a is erected in anopposing relation to the shaft aperture 154. A slide surface portion 159is downwardly provided on the side opposing the operation surfaceportion 146a which opposes and presses the operation pin 115 of thelifter arm 111 of the lifter mechanism (F) from above. A lower edge ofthe slide contact surface portion 159 is formed as a slide contactsurface 159a, and a convex-shaped cam portion 159b which is downwardlyprotruded is continuously formed near the back of the slide contactsurface 159a.

Under the state that the lock plate 145 and the operation plate 146 areoverlapped in the vertical direction, the contact surface portion 157 iscontacted with the inside of the supporting surface portion 153 and thatthe shaft apertures 154 and 158a are communicated with each other, theshaft apertures 154, 158a are communicated with the shaft apertures 140abetween the bearing members 140 of the top plate portion 141 of the base144, to which a supporting point shaft 160 is pivotally supported. Inthis state, the free end 157a of the return leaf spring 157 is urgedagainst the lower surface of the top plate portion 141, and the lockplate 145 is spring-biased by the resilient eccentric cam of the returnleaf spring 157 in such a manner that the engagement surface portion 155side is constantly positioned around the supporting point shaft 160 inthe upper direction.

A torsion coil spring 161 is fitted into an end portion 160a protrudedfrom one bearing member 140 (rear side) of the supporting point shaft160. One end 161a is engaged with the spring engagement member 142aprotruded from the rear edge side of the side wall plate portion 142,and the other end 161b is engaged with the lower edge of one contactsurface portion 158 (rear side) of the operation plate 146, whereby theoperation plate 146 is spring-biased such that the operation surfaceportion 146a is constantly placed in the upper direction.

The slide plate 148 is of substantially L-shape comprising a verticalsurface portion 148a opposing the side wall plate portion 142 of thebase 144 and a horizontal surface portion 148b opposing the bottomsurface plate portion 143. A guide shaft 162 is horizontally protrudedon the inner surface side of the vertical surface portion 148a. Thisguide shaft 162 is inserted into the guide oblong aperture 152 definedin the side wall plate portion 142 and slidably contacted with the loweredge slide contact surface 159b of the slide contact surface portion 159of the operation plate 146. The vertical surface portion 148a has on itsfront end elongated a pressing member portion 163 which is pressed bythe drive mechanism (G). The slider lock 164 which is engaged with thelock arm 150 in the self-maintaining state is fixed to the upper side ofthe rear end portion. A horizontal guide groove 164a opened in the lowerside and whose first half portion is inclined outwardly is formed on theslider lock 164, and the front end surface 164b of the outer side edgeportion of the guide groove 164a is formed as an engagement surfaceportion.

On the other hand, an operation member 165 for elevating the lift lever147 is erected on the front end inside portion of the horizontal surfaceportion 148b of the slide plate 148, protruded from the horizontal guideoblong aperture 143a defined on the bottom surface plate portion 143 ofthe base 141 and opposed to the under side of the lift lever 147. Guideapertures 166 which are long in the front and back direction are formedon the first half portion and the second half portion of the horizontalsurface portion 148b and engaged with the guide pins 167 protruded onthe lower surface of the bottom surface plate portion 143. Further, aspring engagement member 168 is downwardly bent at the rear end insideof the horizontal surface portion 148b and a tension coil spring 169 isextended between the spring engagement member 168 and a springengagement member 143c bent at the front end of the bottom surface plateportion 143, whereby the slide plate 148 is constantly spring-biased soas to be slid in the forward direction relative to the base 141. In thisstate, the guide shaft 162 is slidably contacted with the slide contactsurface 159a of the slide contact surface portion 159 of the operationplate 146 on the side ahead of the convex-shaped cam portion 159b.

The lift lever 147 is of substantially L-shape in a plan view and has anarm portion 147a which is a vertical side portion. The lift lever ispivotally supported at its tip end portion to the side wall plateportion 142 of the base 141, more in detail, the bearing member portion143b is erected on the front end outside portion of the bottom surfaceplate portion 143 by a shaft pin 170 in such a manner that it can berotated in the upper and lower direction. A horizontal side portion isof substantially a quadrilateral, shape in a plan view and a elevatingsurface portion 147b which is opposed to the operation pin 119 of thelifter plate 112 of the lifter mechanism (F) from the lower direction toelevate the operation pin. The elevating surface portion 147bis formedin such a manner that, when the lift lever 147 is rotated in the upperdirection, a second half portion surface 147b₁ becomes a horizontalplane in the upper rotation and a first half portion 147b₂ become ahorizontal plate in the lower rotation. Also, a leg member 171 isprotruded on the lower surface of the rear end (free end) side of thelift lever 147. The aforementioned operation member 165 of the slideplate 147 is opposed to the leg member 171 in the front and backdirection. When the slide plate 148 is slid in the backward direction,the operation member 165 is slidably contacted with the leg member,whereby the lift lever 147 is upwardly rotated about the shaft pin 170.

The return leaf spring 172 is attached to the upper surface of the liftlever 147 and the free end portion 172a thereof is elongated forwardlyby the arm portion 147a and urged against other member so that the liftlever 147 is constantly spring-biased so as to rotate in the lowerdirection. The lock arm 150 that is self-maintained by theelectromagnetic clutch 149 is of substantially L-shape in a plan viewand pivotally supported at its bent portion to the bottom surface plateportion 143 of the base 141. The lock pin 174 which is engaged with theslider lock 164 is implanted on the tip end of the vertical portion 150aand a magnetic member 175 such as iron that can be attracted to theelectromagnetic clutch 149 is attached to the horizontal portion 150b.

The electromagnetic clutch 149 is fixed to the rear surface of thebottom surface plate portion 143 of the base 141 and attracts theaforementioned magnetic member 175 when it is de-energized, and releasesthe magnetic member from being attracted when it is energized. When theelectromagnetic clutch is de-energized, under the condition that theslide plate 148 is slid backwards, the electromagnetic clutch attractsthe magnetic member 175 of the lock arm 150 and holds the lock arm 150in the rotating state, whereby the lock pin 174 is engaged with theslider lock 164 of the slide plate 148, resulting in the slide plate 148being locked and held. When the electromagnetic clutch is energized, theelectromagnetic clutch releases the magnetic member 174 from beingattracted and the lock arm 150 is rotated in the opposite direction bythis repulsive operation, thereby releasing the slide plate 148 frombeing locked. As a result, the slide plate 148 is slidably returned tothe forward under spring-biasing force of the tension coil spring 169.

The lock releasing plate 151 is attached to the side wall plate portion142 of the base 141 so as to become slidable along the inner surface inthe front and back direction. The lock releasing plate is insertedbetween the slider lock 164, which is attached to the slide plate 148 soas to oppose the upper direction of the bottom surface plate 143, andthe side wall plate portion 142 by the operation member 60c of the lockarm 150 when the aforementioned slider apparatus (A-c) is slidbackwardly, thereby releasing the lock arm 150 from being locked. Ahorizontally oblong guide aperture 176 is defined in the side wall plateportion 151a which is parallel to the side wall plate portion 142 andengaged with the guide pin 177 horizontally protruded from the side wallplate portion 142. A lower surface portion 151b is horizontally providedon the lower edge of the side surface portion 151a, and a lock releasingportion 151b₁ is formed on the rear inside of the lower surface portion151b. An engagement portion 178 which is engaged with the rear endoperation member 60c of the slider apparatus (A-c) is formed on thefront end portion of the side surface portion 151a, and an upper surfaceportion 151c is formed from the first half upper edge. Then, a springengagement member 179 is downwardly bent at the rear end of the uppersurface portion 151c.

A tension coil spring 181 is extended between the spring engagementmember 179 of the lock releasing plate 151 and a spring engagementmember 180 protruded from the lower edge of the front side bearingmember 140 of the base 141 to thereby constantly spring-bias the lockreleasing plate 151 in the forward direction.

A sensor 183 for detecting whether or not the slide plate 148 is slid inthe backward direction is fixed to the rear end portion of the side wallplate portion 142 of the base 144 through an attachment plate 182. Thesensor 183 may be a photointerrupter. A shield plate 184 is attached tothe rear end of the vertical surface portion 148a of the slide plate 148as a detection member in response to the sensor 183.

Operation of the thus arranged magneto-optical disk apparatus will bedescribed with reference to FIGS. 22 to 31.

When the magneto-optical disk apparatus is not operated, i.e., in thestate where the disk cartridge 201 is not loaded, the left and rightsliders 51L, 51R of the slider apparatus (A-c) are locked by the diskcartridge lock apparatus (A-b) in the cartridge holder 9 under thecondition that they are slid backwards. Thus, the cartridge holder islocated at the elevated position.

Specifically, the disk cartridge lock apparatus (A-b) is outwardlyrotated under spring force of the torsion spring 46 and engaged with theengagement pin 45 protruded on the cartridge holder 9 in the engagementportion 44a of the cam groove 44 under the condition that the slide base35 is slid in the forward direction and the lock arm 36 is faced withinthe rear portion of the cartridge holder 9. Under this state, theinterlocking arm 37 is pivotally supported to the cartridge holder 9 andthe first engagement pin 48 is engaged with the slide base 35. Thesecond engagement pin 49 of the interlocking arm 37 is engaged with theengagement groove 58 of the left slider 51L (see FIG. 23), whereby therespective sliders 51L, 51R are locked under the condition that it isslid backwards against the spring force of the tension coil spring 67.Therefore, as shown in FIG. 9, the first and second parallel cam grooves54a, 54b of the high position of the respective side sliders 51L, 51Rare engaged with the first and second pins 34a, 34b, whereby thecartridge holder 9 is held at the elevated position.

Under this condition, the first and second elevating plates 70, 71 ofthe elevating mechanism (C) are lowered because the third and fourthinclined cam grooves 57a, 57b of the respective sliders 51L, 51R areabutted against the cam pin 75 and the shaft pin 73, whereby the spindlemotor 10 attached to the first elevating plate 70 also is lowered andthe fixed portion 68a of the spindle operation member 68 is fullyinserted into the opening portion 15a of the spindle motor positioningmember 15. The cartridge positioning pin 74 implanted on the secondelevating plate 71 is also placed at the lower position by the cartridgeholder 9 (see FIG. 9).

In this manner, the cartridge holder 8 is held under the condition thatit is communicated with the cartridge insert and eject mouth 5 of thefront panel 4.

On the other hand, the operation pin 6b of the slide operation portion60 is slidably contacted with the lower edge surface of the cam surfaceportion 156 when the slider apparatus (A-c) is slid in the backwarddirection, whereby the lock plate 145 of the transmission mechanism (H)rotates the engagement surface portion 155 downwardly so that thecomb-tooth 155a is downwardly engaged with the operation pin 115 of thelifter arm 111 of the lifter mechanism (F) with a pressure.

Therefore, the lifter arm 111 of the lifter mechanism (F) is rotatedupwardly about the shaft pin 114 of the engagement plate 113 relative tothe carriage 82 of the optical pickup device (D) until the upper edge ofthe upper-stage concave portion 116a is engaged with the engagement pin118 of the lifter plate 112 so that its horizontal side portion 111araises the head arm 101 of the external magnetic field applyingapparatus 100 (E) thereby to hold the magnetic field applying head 100at the uppermost position, i.e., at the a distal position from themagneto-optical disk 202 as shown in FIG. 29. Moreover, in this state,the carriage 82 is locked through the lifter arm 111 and therebyprevented from being moved and fluctuated inadvertently.

Accordingly, when the disk cartridge 201 is inserted into the cartridgeholder 9 provided within the housing 3 from the cartridge insert andeject mouth 5 of the front panel 4, the shutter opening pin 23 of theshutter opening apparatus (A-a) of the cartridge holder 9 comes incontact with the front surface portion 209, thereby being engaged withthe tip end of the slide guide member 214 of the shutter member 211 asshown in FIG. 22.

Further, when the disk cartridge 201 is inserted into the cartridgeholder 9 as shown in FIG. 23, the shutter opening pin 23 is moved alongthe inclined portion 22a of the cam groove 22 by the pressure of thedisk cartridge 201. At that time, the shutter releasing pin supportingmember 24 is rotated along the inclined groove 22a of the cam groove 22against a spring force of the tension coil spring 26 while changing theposition at which the guide groove 24c is engaged with the guide pin 25is being changed.

As a consequence, the shutter member 211 is slid against aspring-biasing force of a torsion coil spring (not shown) providedwithin the cartridge 203 in the direction shown by an arrow 0 in FIG.23, i.e., in the direction in which the opening portions 206, 216 of thedisk cartridge 201 are opened.

Then, if the disk cartridge 201 is further inserted into the cartridgeholder 9, then the shutter opening pin 23 is moved along the arcuateportion 22b of the cam groove 22 in the direction of the straight lineportion 22c, whereby the shutter member 211 is slid in the direction inwhich the opening portions 206, 216 of the disk cartridge 201 areopened.

When the disk cartridge 201 is inserted with a pressure and the shutteropening pin 23 is reached to the rear end portion of the arcuate portion22b, as shown in FIG. 24, the shutter opening pin is entered into theshutter opening member fitting portion 224 of the cartridge 203.

On the other hand, since the disk cartridge 201 is inserted with apressure, the mis-insertion preventing grooves 207a, 208a defined insubstantially the first half portion of the lower half 205 of thecartridge 203 oppose the engagement tab members 29 inwardly bent on thesecond half portion near the rear of the central portions of therespective side surface portions of the cartridge holder 9 with theresult that the disk cartridge 201 is continuously inserted into thecartridge holder 9 under the condition that the mis-insertion preventinggrooves 207a, 208a are slidably contacted with the engagement tabmembers 29.

In that case, when a disk cartridge different from the disk cartridge201 is inserted into the cartridge holder 9, such different diskcartridge is prevented from being inserted into the cartridge holder 9more than ever by the engagement tab members 29. Specifically, themis-insertion of a disk cartridge having a similar shape can beprevented by forming protrusions such as the engagement tab members 29or the like on the cartridge holder 9 side.

As a consequence, when the opening portions 206, 216 of the diskcartridge 201 are fully opened and the disk cartridge 201 is furtherinserted into the cartridge holder 9, the lock arm 36 of the frontsurface portion 209 of the disk cartridge 201 is contacted with thetrigger pin 42 of the lock arm 36.

When the disk cartridge 201 is further inserted into the cartridgeholder 9, the shutter opening pin 23 is moved in the cartridge insertiondirection along the straight line portion 22c of the cam groove 22 andthe shutter opening pin supporting member 24 is rotated rear against thespring force of the tension coil spring 26.

Then, when the disk cartridge 201 is further inserted into the cartridgeholder 9, as shown in FIG. 24, the lock arm 36 is moved in the backwarddirection together with the slide base 35 through the trigger pin 42. Ifthe engagement portion 44a of the cam groove 44 is detached from theengagement pin 45 protruded on the cartridge holder 9 side when the lockarm 36 is slid, then the lock arm 36 is rotated and the cartridge holdpin 43 is fitted and engaged into one side portion of the disk cartridge201, i.e., the pin engagement aperture 228 of one mis-insertionpreventing groove 207a, whereby the disk cartridge 201 is held and theshutter member 211 is finally brought in contact with the cartridgeinsertion position restricting member 201. Thus, the loading position ofthe disk cartridge 201 is determined. Under this condition, the shutteropening pin supporting member 24 is considerably rotated in the backwarddirection and then positioned.

Although the rotation range of the lock arm 36 in this case falls withinthe range in which the cartridge hold pin 43 is fitted into andextracted from the pin fitting aperture 228 of the disk cartridge 201,the pin fitting aperture 228 is defined on the side surface of themis-insertion preventing groove 207a of the disk cartridge 201.Therefore, under the condition that the cartridge hold pin 43 isextracted, the cartridge hold pin is placed at the position in which itis not protruded from the width of the cartridge 203, thereby making itpossible to reduce the width of the disk apparatus and to miniaturizethe apparatus.

Concurrently with this operation, when the slide base 35 is slid, theinterlocking arm 37 is rotated and the second engagement pin 49 isdetached from the engagement groove 58 of the left slider 51L of theslider apparatus (A-c).

Thus, the slider apparatus (A-c) is released from being locked with theresult that the respective sliders 51L, 51R are slid in the forwarddirection under the spring force of the tension coil spring 67. When therespective sliders 51L, 51R are slid in the forward direction, thesecond-half parallel cam grooves 55a, 55b of low position of therespective sliders 51L, 51R are engaged with the first and second pins34a, 34b so that the cartridge holder 9 is held at the lowered position.

In this state, the disk cartridge 201 inserted into and held within thecartridge holder 9 is placed on the reference supporting portion 12formed on the chassis 1 and also downwardly pressed by the press springmember 31 attached to the cartridge holder 9 and urged against thereference supporting portion 12, thereby held at a predetermined heightdirection.

The third and fourth inclined cam grooves 57a, 57b of the respectivesliders 51L, 51R are opposed to the cam pin 75 and the shaft pin 73 ofthe respective sides in the high position, whereby the first and secondelevating plates 70, 71 of the elevating mechanism (C) are elevated.

As a result, the cartridge positioning pins 74 implanted on the secondelevating plate 71 are fitted into the cartridge positioning pinengagement apertures 225, 226 of the cartridge 203, there by the diskcartridge 201 being positioned.

Moreover, in this state, the circumferential surface of the centralcircular opening portion 206b of the lower half 205 of the cartridge 203is opposed to the upper surface of the spindle motor positioning member15, whereby the coupling surface 205a between the circular openingportion 206b and the rectangular opening portion 206a is brought incontact with the supporting protrusion surface 15c and other portionsurface is brought in contact with the supporting protrusion surface15d.

Concurrently with this operation, the spindle motor 10 attached to thefirst elevating plate 70 also is elevated so that the rotary portion 68aof the spindle holding member 68 is protruded from the opening portion15a of the spindle motor positioning member 15 and held at apredetermined height position.

Therefore, the rotary portion 68a of the spindle holding member 68 isinserted into the circular opening portion 206b of the lower half 205 ofthe cartridge 203, whereby the disk resting surface 68a₁ of itsperipheral edge contacts with the chucking hub 202a of themagneto-optical disk 202 and the spindle shaft 10a is inserted into thecentral aperture, thereby the magneto-optical disk 202 being chucked tothe spindle motor 10.

As described above, the magneto-optical disk 202 is loaded onto themagneto-optical disk apparatus.

Under the condition that the disk cartridge 201 is loaded and thechucking of the magneto-optical disk 202 onto the spindle motor 10 iscompleted, the locking of the optical pickup device (D) is released.

Specifically, when the slider apparatus (A-c) is slid in the forwarddirection, the operation pin 60b of the slide operation portion 60 isdetached from the cam surface portion 156 of the lock plate 145 of thetransmission mechanism (H), whereby the lock plate 145 is returned androtated by the return spring 157 to move the engagement surface portion155 side in the upper direction and the comb-shaped tooth 155a isdetached from the operation pin 115 of the lifter arm 111 of the liftermechanism (F), thus the locking of the carriage 82 being released.

In this state, as shown in FIG. 30, in the lifter mechanism (F), thelifter arm 111 is rotated until the lower edge of the upper-stageconcave portion 16a of the engagement plate 113 is engaged with theengagement pin 118 of the lifter arm plate 112 under spring force of thetorsion coil spring 122. As a consequence, the height of thestraightened head arm 101 is lowered so that the magnetic field applyinghead 100 is held in such a manner that it is slightly floated from thesurface of the magneto-optical disk 202.

If it is detected by the detection switch 76A or 76B that themagneto-optical disk 202 is the ROM (read-only) disk, then the recordingmagnetic field applying head 100 is not utilized. Therefore, under thecondition that the magnetic field applying head 100 shown in FIG. 30 isfloated from the surface of the magneto-optical disk 202, the opticalpickup device (D) is actuated and operated. Also, after the focusing isturned on by rotating the spindle motor 10, the ordinary read sequenceis carried out.

If on the other hand it is detected by the detection switch 76A or 76Bthat the magneto-optical disk is the RAM disk, then the magnetic fieldapplying head 100 is loaded onto the magneto-optical disk 202 asfollows.

Specifically, when the RAM disk is detected, the carriage 82 is moved toa specific position in the radial direction of the magneto-optical disk202 by applying a drive current to the coil 87. Then, the drive motor130 of the drive mechanism (G) is driven such that the transmission gear132 is rotated in the direction shown by an arrow R₂ in FIG. 15. Thus,when the transmission gear 132 is rotated in the arrow R₂ direction, thepin 131 presses the press member portion 163 to slide the slide plate148 of the transmission mechanism (H) in the backward direction.

The slide plate 148 is slid in the backward direction, whereby theoperation member 165 upwardly rotates the lift lever 147 such that thelift lever is slid over the leg portion 171 formed on the lower surface.When this soft lever 147 is rotated, the pushing surface portion 147bpushes the operation pin 119 of the lifter plate 112 of the liftermechanism (F) to rotate the lifter plate 112 against the spring force ofthe torsion coil spring 122, whereby the engagement pin 118 is engagedwith the lower-stage concave portion 116b of the engagement plate 113.As a result, as shown in FIG. 31, the lifter arm 111 is downwardlyrotated around the shaft pin 114 of the engagement plate 113, wherebythe horizontal side portion 111a of the lifter arm is detached from thelower surface side of the head arm 101. Thus, the head arm 101 is movedin the lower direction, and hence the magnetic field applying head 100is brought in contact with the surface of the magneto-optical disk 202.Then, in the lifter arm 111, the engagement pin 118 is engaged with thelower-stage concave portion 116b, whereby the contact of the magneticfield head 100 with the disk 202 is kept.

In this operation, when the slide plate 148 is slid in the backwarddirection, the guide groove 164a of the slider lock 164 is fitted intothe lock pin 174 of the lock arm 150 to rotate the lock arm 150. Underthis state, the electromagnetic clutch 149 is energized and the lock armis attracted by the electromagnetic clutch 149 through the magneticmember 175.

In this state, the engagement surface portion 164b of the slider lock164 is engaged with the lock pin 174 of the lock arm 150, whereby theslide plate 148 is locked under the condition that it is slid backwards.

Consequently, the lift lever 147 is rotated upwardly and held in thisstate. By reversing the rotation of the drive motor 130, a rotationalforce in the direction shown by the arrow R₁ in FIG. 15 is being appliedto the transmission gear 132 until the pin 131 is displaced to the fixedposition a shown in FIG. 15.

In this manner, the loading operation of the magnetic field applyinghead 100 is executed.

Thereafter, the carriage 83 is moved in the radius direction of themagneto-optical disk 202, and after the focusing is turned on byrotating the spindle motor 10, the ordinary read/write sequence iscarried out.

The unloading operation of the magnetic field applying head in themagneto-optical disk apparatus will be described next.

Initially, the spindle motor 10 is stopped in response to an ejectcommand from a host computer or the like.

Then, a releasing pulse voltage is applied to the electromagnetic clutch149, whereby the lock arm 150 is released from being attracted andbecomes rotatable. As a result, the slide plate 148 is placed in thelock released state and returned and slid by a spring-biasing force ofthe tension coil spring 169.

When the slide plate 148 is returned and slid, the lift lever 147 isdownwardly moved and slid to release the operation pin 119 of the lifterplate 112 from pushing. Also, the guide shaft 162 of the slide plate 148is slidably contacted with the convex cam portion 159b, whereby theoperation surface portion 146a of the operation plate 146 is lowered torotate the operation plate, thereby downwardly pressing the operationpin 115 of the lifter arm 111. Consequently, the lifter arm 111 of thelifter mechanism (F) is upwardly rotated around the shaft pin 114 of theengagement plate 113 relative to the carriage 82 of the optical pickupdevice (D) until the upper edge of the upper-stage concave portion 116ais engaged with the engagement pin 118 of the lifter plate 112. Thus,the horizontal side portion 111a linearly elevates the head arm 101 ofthe external magnetic field generating apparatus (E) so that themagnetic field applying head 100 is held at the uppermost position,i.e., at the position largely spaced apart from the magneto-optical disk202 as shown in FIG. 29. Moreover, in this state, the carriage 82 islocked through the lifter arm 111 and thereby prevented from being movedand fluctuated inadvertently.

Then, the drive motor 130 applies the rotational force (reverse force)in the direction shown by the arrow R₁ to the transmission gear 132until the pin 131 is displaced from the fixed position a to the fixedposition b as shown in FIG. 14. At that time, by the rotation of thetransmission gear 132, the pin 131 is engaged with the engagementportion 60a of the slide operation portion 60 of the right slider 51R ofthe slider apparatus (A-c) to press the right slider in the backwarddirection. Thus, the sliders 51L, 51R are returned from the loadingposition to the unloading position against the spring-biasing force ofthe tension coil spring 67, whereby the operation pin 60b of the slideoperation portion 60 is slidably contacted with the lower edge surfaceof the cam surface portion 156 of the lock plate 145, resulting in thelock plate 145 being rotated so as to lower the engagement surfaceportion 155 side.

As a consequence, the comb-shaped tooth 155a of the lock plate 145engages with and presses the operation pin 115 of the lifter arm 111 inthe lower direction so that the lifter arm 111 is further rotatedupwardly as shown in FIG. 29. Thus, the magnetic field applying head 100is detached from the magneto-optical disk 202 and the carriage 82 islocked.

As described above, the sliders 51R, 51L of the slider apparatus (A-c)are returned to the unloading position, whereby the cartridge holder 9is elevated by the operation opposite to the unloading operation and thefirst and second elevating plates 70, 71 are lowered. As a result, thespindle motor 10 is detached from the chucking hub 202a of themagneto-optical disk 202 and lowered and fully inserted into the spindlemotor positioning member 15. In that case, the circumferential surfaceof the central circular opening portion 206b of the lower half 205 ofthe disk cartridge 201 is brought in contact with the supportingprotrusion surfaces 15c, 15d of the upper surface of the spindle motorpositioning member 15 and thereby held down. In particular, since thecoupling surface 205a which is the thin portion is held down by the widesupporting protrusion surface 15c, the cartridge 203 can be preventedfrom being deformed and damaged.

Moreover, the disk cartridge 201 is released from being held down on thereference supporting portion 12 and the cartridge positioning pins 74are extracted from the cartridge positioning pin engagement apertures225, 226.

Then, since the slider apparatus (A-c) is slidably returned, the secondengagement pin 49 is engaged with the engagement groove 58 of the leftslider 51L so that the interlocking arm 37 pivotally supported to thecartridge holder 9 is rotated to slide the slide base 35 in the forwarddirection.

As a result, the lock arm 36 is rotated to detach the cartridge hold pin43 from the pin fitting aperture 228 of the disk cartridge 201.

Therefore, the disk cartridge 201 becomes movable relative to thecartridge holder 9 so that the disk cartridge is pressed and moved inthe cartridge eject direction through the shutter opening pin 23 underreturn spring force of the tension coil spring 26.

Then, when the disk cartridge 201 is further moved in the cartridgeeject direction, the shutter opening pin 23 is passed through thearcuate portion 22b of the cam groove 22 and moved along the inclinedgroove 22a.

At that time, the shutter member 211 is moved under spring force of atorsion spring (not shown) provided within the cartridge 203 in thedirection in which the opening portions 206, 216 of the disk cartridge201 are closed.

Further, when the disk cartridge 201 is moved in the cartridge ejectdirection, as shown in FIG. 21, the shutter opening pin 23 is spacedapart from the front surface portion 209 of the disk cartridge 201 sothat substantially the second half portion of the disk cartridge 201 isejected to the outside of the cartridge holder 9. As described above,the disk cartridge 201 is unloaded from the magneto-optical diskapparatus.

When the operation of the magneto-disk apparatus is stopped due to theinterruption of power by a power failure during the magneto-optical disk202 is read and/written, in order to eject the disk cartridge 201without awaiting the supply of power, the user should insert apin-shaped operation tool from the front surface panel 4 side to pressone slider of the slider apparatus (A-c), the right slider 51R in thisembodiment, thereby sliding the slider apparatus (A-c) against thespring-biasing force of the tension coil spring 67 in the backwarddirection, i.e., unloading position direction.

Therefore, the operation member 60c of the slide operation portion 60abuts against the engagement portion 178 of the lock releasing plate151, thereby the lock releasing plate 151 being backwards.

The lock releasing plate 151 is slid backwards so that the lockreleasing portion 151b, at the inner rear portion of the lower surfaceportion 151b abuts against the vertical portion 150a on which the lockpin 174 of the lock arm 150 attracted and held by the electromagneticclutch 149 is implanted, whereby the horizontal portion 150b to whichthe magnetic member 175 is attached is pressed and the lock arm 150 isrotated.

Concurrently with the rotation of the lock arm 150, the lock pin 174 ismoved from the engagement surface portion 164b side of the slider lock164 of the slide plate 148 to the guide groove 164a, whereby the lockedstate of the slide plate 148 is released.

As a result, the slide plate 148 is returned and slid underspring-biasing force of the tension coil spring 169 similarly to thecase where the locked state of the slide plate 148 is released onapplication of the releasing pulse voltage to the electromagnetic clutch149.

When the slide plate 148 is returned and slid, the lift lever 147 islowered to release the lifter plate 112 from upwardly pushing theoperation pin 119. Also, the operation plate 146 is rotated such thatthe guide shaft 162 of the slide plate 148 is slidably contacted withthe convex cam portion 159b so as to lower the operation surface portion146a, thus the operation plate pressing the operation pin 115 of thelifter arm 111 from the upper direction.

Consequently, the lifter arm 111 is rotated upwardly to cause themagnetic field applying head 100 to be spaced apart from themagneto-optical disk 202. In this state, when the slider apparatus (A-c)is further pressed and slid in the backward, the magnetic disk apparatusis operated similarly to the aforementioned unloading operation, wherebythe disk cartridge 201 can be ejected and unloaded.

As described above, in the magnetic disk apparatus according to thisembodiment, upon emergency such as occurrence of power failure ortrouble, without damaging the magneto-optical disk 202 and the magneticfield applying head 201, the user can unload the disk cartridge 201 in amanual fashion.

Another embodiment of the cartridge holder 9 will be described withreference to FIGS. 32 to 34, wherein parts formed similarly to those ofthe aforesaid cartridge holder 9 are marked with the same references andneed not be described.

The cartridge holder 9 according to this embodiment is provided with amis-insertion preventing and disk cartridge mis-eject preventingmechanism 901 instead of one engagement pawl tab 29 of the engagementtabs 29, 29 serving as the cartridge mis-insertion preventing meansformed on both side surfaces of the cartridge holder 9.

Specifically, the mis-insertion preventing and disk cartridgemis-unloading preventing mechanism 901 includes an engagement member 902and a tension coil spring 903 serving as the biasing means for biasingthis engagement member 902. The engagement member 902 comprises anengagement portion 902b erected at the rear end of a plate-shapedportion 902a, a vertical oblong aperture 902c defined at the centralportion and a cam edge 902d formed at the front end portion.

Under the condition that the engagement portion 902b formed at the rearend is inwardly protruded from the recess portion 20a defined on theguide supporting portion 20 to the lower surface at substantially thecentral portion of one guide supporting portion 20 of the cartridgeholder 9, this engagement member 902 can be rotated and slid in thefront and back direction by a shaft pin 904 inserted into the guideaperture 902c and slidably biased in the backward direction by thetension coil spring 903. In this state, the engagement portion 902b ofthe engagement member 902 is opposed to the engagement pawl tab 29inwardly bent on other side surface of the cartridge holder 9. Also, thespacing between the upper end edge and the top plate 9a in theengagement portion 902 is equal to or slightly larger than the thicknessT of the side surface portion of the upper half 204 corresponding to themis-insertion preventing grooves 207a, 208a of the disk cartridge 201.

When this engagement member 902 is slid in the forward direction againstthe biasing force of the tension coil spring 903, the cam edge 902d atthe front end is slidably contacted with the protrusion 20b protruded atthe guide supporting portion 20 and thereby outwardly rotated around theshaft pin 904 with the result that the engagement portion 902b is movedto the inner side surface of the cartridge holder 9, i.e., theengagement portion is escaped from the insertion portion of the diskcartridge 201.

Since the cartridge holder 9 is provided with the mis-insertionpreventing and disk cartridge mis-eject preventing mechanism 901 asdescribed above, when the 3.5-inch size microfloppy disk cartridgedifferent from the aforementioned disk cartridge 201 is inserted intothe disk cartridge, one corner portion of the end face of the dish shellabuts against the engagement portion 902b of the engagement member 902and the other corner portion abuts against the engagement pawl tab 29 ofthe cartridge holder 9, respectively, so that the microfloppy diskcartridge can be prevented from being inserted into the cartridgeholder. Even when the disk cartridge 201 is inserted into the cartridgeholder in the opposite direction, i.e., from the rear surface side, onecorner portion of the rear end face abuts against the engagement portion902b of the engagement portion 902 and the other corner portion abutsagainst the engagement pawl tab 28, respectively, so that such diskcartridge can be prevented from being mis-inserted into the cartridgeholder.

Then, when the disk cartridge 201 is correctly inserted into thecartridge holder, the disk cartridge is continuously inserted into thecartridge holder 9 under the condition that the mis-insertion preventinggroove 207a on the side surface 207 side of the cartridge 207 isslidably contacted with the engagement pawl tab 29 and the mis-insertionpreventing groove 208a on the side surface 208 side is slidablycontacted with the engagement portion 902b of the engagement member 902.In that case, since the engagement portion 902b of the engagementportion 902 is slidably urged against the side surface of themis-insertion preventing groove 208a defined on the side surface 208side of the cartridge 203 of the disk cartridge 201 under biasing forceof the tension coil spring 903, if the pin insertion aperture 229elongated from the mis-insertion preventing groove 208a is opposed tothe engagement portion 902b of the engagement member 902, then theengagement member 902 is inwardly rotated under biasing force of thetension coil spring 903 and the engagement portion 902b is entered intoand engaged with the pin insertion aperture 229 with the result that thedisk cartridge 201 is temporarily placed in the engaged state. However,the disk cartridge 201 is inserted into the pin insertion aperture witha pressure larger than the biasing force of the tension coil spring 903,whereby the engagement member 902 is rotated in the outside and releasedfrom the engaged state. Thus, the insertion of the disk cartridge iscontinued and the disk cartridge is inserted into and held within thecartridge holder 9 similarly as described above.

As described above, in the unloading operation for unloading the diskcartridge 201 from being locked within the cartridge holder 9, i.e., inthe eject operation in which the disk cartridge 201 is resilientlyejected from the cartridge holder 9, if the side surface of themis-insertion preventing groove 208a on the side surface 208 side of thedisk cartridge 201 is slidably contacted with the engagement portion903b of the engagement member 902 and the pin insertion aperture 229 isopposed to the engagement portion 903b, then the engagement member 902is rotated under biasing force of the tension coil spring 903 so thatthe engagement portion 903b is inserted into and engaged with the pinfitting aperture 229. As a consequence, the disk cartridge 201 isengaged and held under the condition that the second half portionthereof is projected from the cartridge insert and eject mouth 18 of thecartridge holder 9 (see FIG. 34). In this state, the user removes andejects the disk cartridge 201 from the cartridge 9 manually. When thedisk cartridge 201 is ejected from the cartridge holder 9, the diskcartridge is temporarily engaged and held which it is being ejected.Therefore, the disk cartridge can be prevented from being ejected fromthe cartridge holder 9 inadvertently and the disk cartridge 201 can beprevented from being damaged.

While the embodiments of the present invention have been described sofar, although the expression of forward and the expression of backwardare used in this description, the forward means the disk cartridgeinsertion mouth side and the backward means the disk cartridge insertiondepth direction.

Further, the present invention is not limited to the illustratedembodiments and may be variously modified without departing from thegist of the present invention. For example, shapes of respective membersmay be changed arbitrarily so long as they are operated similarly. Thespring member serving as the spring-biasing member may use arbitrarily acoil spring, a leaf spring or the like.

While the embodiments are applied to the magneto-optical disk apparatushaving the carriage for holding the objective lens and the magneticfield applying head as described above, the present invention may beapplied to an optical disk apparatus which does not use the magneticfield applying head.

As described above, according to the recording and reproducing apparatusof the present invention, the loading operation and the unloadingoperation of the disk cartridge can be carried out stably and smoothly.Also, the disk can be chucked to the rotary drive mechanism stably andreliably.

Further, the head means can be reliably opposed to the disk and can bereliably held in the state which does not bother the loading andunloading of the disk cartridge.

The mis-insertion of the 3.5-inch size microfloppy disk can be preventedreliably and only a predetermined magneto-optical disk can berecorded-and reproduced reliably.

We claim:
 1. A disk cartridge in which a recording disk is stored in aspace formed by fastening an upper half and a lower half, said upperhalf having a groove portion and a rib portion, said groove portionextended from a front end to a central portion direction to oppose amis-insertion preventing protrusion formed on at least one side surfaceof said lower half,wherein an engagement concave portion is formed onthe inner surface of said groove portion engaged with and held by aholding member within said disk drive when said disk cartridge is loadedonto said disk drive; and further wherein a lower edge of said ribportion corresponds to the surface of said groove portion, such that thethickness of said rib portion is less than the thickness of said upperhalf, said groove portion being substantially perpendicular to a sidesurface of said rib portion.
 2. The cartridge of claim 1, wherein saidupper half and said lower half have provided on their front surfaceportions opening portions for exposing a part of a signal recordingsurface of a stored recording disk to the outside, and further, whereinsaid cartridge includes a shutter member slidably provided thereon foropening and closing said opening portions.
 3. The cartridge of claim 1,wherein said groove portion is formed on left and right side surfaces ofsaid upper half.
 4. The cartridge of claim 3 wherein said openingportions include a rectangular opening portion and a circular openingportion.
 5. The cartridge of claim 1, wherein said groove portion has abottom surface extending from said upper half to said lower half.
 6. Thecartridge of claim 1, wherein said groove portion has a substantiallyL-shaped cross section.
 7. A disk cartridge in which a recording disk isstored in a space formed by fastening an upper half and a lower half,said upper half having a pair of groove portions and rib portions, eachof said groove portions extended from a front end to a central portiondirection to oppose a mis-insertion preventing protrusion formed on atleast one side surface of said lower half,wherein engagement concaveportions formed on the inner surfaces of said respective groove portionsare engaged with and held by a holding member within said disk drivewhen said disk cartridge is loaded onto said disk drive and a width of aspacing between said groove portions is smaller than a width of a3.5-inch size microfloppy disk shell; and further wherein a lower edgeof each of said rib portions corresponds to the surface of saidcorresponding groove portions, respectively, such that the thickness ofsaid rib portion is legs than the thickness of said upper half, saidgroove portion being substantially perpendicular to a side surface ofsaid rib portion.
 8. The cartridge of claim 7, wherein a maximum widthof said disk cartridge is equal to or larger than said width of said3.5-inch size microfloppy disk shell.
 9. The cartridge of claim 7wherein each of said rib portions are elongated from said respectivegroove portions, and further, wherein a dimension from the top of onerib portion to the top of the other rib portion is substantially equalto the width of said 3.5-inch size microfloppy disk shell.
 10. Thecartridge of claim 9, wherein said rib-shaped portions are formed onleft and right side surfaces of said lower half.
 11. The cartridge ofclaim 7, wherein a diameter of said recording disk is 88 mm, a maximumwidth of said cartridge is 92 mm and a spacing between said two grooveportions is 87 mm.
 12. The cartridge of claim 7, wherein said grooveportions are formed adjacent to said space in which said recording diskis stored.
 13. A disk cartridge in which a recording disk is stored in aspace formed by fastening an upper half and a lower half, said upperhalf and said lower half have provided on their front surface portions aplurality of opening portions for exposing a part of a signal recordingsurface of a stored recording disk to the outside, said upper halfhaving a plurality of groove portions and rib portions, each of saidgroove portion having a bottom surface extending from said upper half tosaid lower half and extending from a front end to a central portiondirection to oppose a mis-insertion preventing protrusion formed on atleast one side surface of said lower half,wherein an engagement concaveportion is formed on the inner surface of each of said groove portionsengaged with and held by a holding member within said disk drive whensaid disk cartridge is loaded onto said disk drive; wherein a lower edgeof said each rib portion corresponds to the surface of said respectivegroove portion, such that the thickness of said rib portion is less thanthe thickness of said upper half, said groove portion beingsubstantially perpendicular to a side surface of said rib portion; andfurther wherein said cartridge includes a shutter member slidablyprovided thereon for opening and closing said opening portions.
 14. Thecartridge of claim 13 wherein said groove portions are formed on leftand right side surfaces of said upper half, respectively.
 15. Thecartridge of claim 14 wherein said opening portions include arectangular opening portion and a circular opening portion.
 16. Thecartridge of claim 15 wherein each of said groove portions has asubstantially L-shaped cross section.
 17. The cartridge of claim 16wherein a spacing between said two groove portions is 87 mm.
 18. Thecartridge of claim 13 wherein said opening portions include arectangular opening portion and a circular opening portion.
 19. Thecartridge of claim 13 wherein a spacing between said two groove portionsis 87 mm.